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23  WEST  MAIN  STREET 

WEBSTER,  N.Y.  14580 

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Technical  and  Bibliographic  Notes/Notes  techniques  et  bibliographiques 


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The  Institute  has  attempted  to  obtain  the  best 
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I      I    Cover  title  missing/ 


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Coloured  maps/ 

Cartes  giographiques  en  couieur 


□    Coloured  ink  (i.e.  other  than  blue  or  black)/ 
Encre  de  couieur  (i.e.  autre  que  bleue  ou  noire) 

nn    Coloured  plates  and/or  illustrations/ 


D 


Planches  et/ou  illustrations  en  couieur 


Bound  with  other  material/ 
Relii  avac  d'autres  documents 


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La  re  liure  sorree  peut  causer  de  I'ombre  ou  de  la 
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Additional  comments:/ 
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une  image  reproduite,  ou  qui  peuvent  exiger  una 
modification  dans  la  methods  normale  de  filmage 
sont  indiqu6s  ci-dessous. 


n 

n 

D 

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n 


Coloured  pages/ 
Pages  de  couieur 

Pages  damaged/ 
Pages  endommagdes 

Pages  restored  and/or  laminated/ 
Pages  restauries  et/ou  pelliculdes 

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ensure  the  best  possible  image/ 
Les  pages  totalement  ou  partiellement 
obscurcies  par  un  feuillet  d'errata.  une  pelure, 
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to  the  generosity  of: 

University  of  Sasltatchewan 
Saskatoon 

The  images  appearing  here  are  the  best  quality 
possible  considering  the  condition  and  legibility 
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filming  contract  specifications. 


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g6n6rosit6  de: 

University  of  Saskatchewan 
Saskatoon 

Les  images  suivantes  ont  6t6  reproduites  avec  le 
plus  grand  soin,  compte  tenu  de  la  condition  et 
de  la  nettetd  de  l'exemplaire  film6,  et  en 
conformity  avec  les  conditions  du  contrat  de 
filmage. 


Original  copies  in  printed  paper  covers  are  filmed 
beginning  with  the  front  cover  and  ending  on 
the  last  page  with  a  printed  or  illustrated  impres- 
sion, or  the  back  cover  when  appropriate.  All 
other  original  copies  are  filmed  beginning  on  the 
first  page  with  a  printed  or  illustrated  impres- 
sion, and  ending  on  the  last  page  with  a  printed 
or  illustrated  impression. 


The  last  recorded  frame  on  each  microfiche 
shall  contain  the  symbol  -—^'  (meaning  "CON- 
TINUED ").  or  the  symbol  V  (meaning  "END"), 
whichever  applies. 


Les  exemplaires  originaux  dont  la  couverture  en 
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dernidre  page  qui  comporte  une  empreinte 
d'impression  ou  d'illustration,  soit  par  le  second 
plat,  selon  le  cas.  Tous  les  autres  exemplaires 
originaux  sont  filmds  en  commenqant  par  la 
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d'impression  ou  d'illustration  et  en  terminant  par 
la  dernidre  page  qui  comporte  une  telle 
empreinte. 

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dernidre  image  de  cheque  microfiche,  selon  le 
cas:  le  symbole  — ►  signifie  "A  SUIVRE".  le 
symbole  V  signifie  "FIN". 


Maps,  plates,  charts,  etc.,  may  be  filmed  at 
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entirely  included  in  one  exposure  are  filmed 
beginning  in  the  upper  left  hand  corner,  left  to 
right  and  top  to  bottom,  as  many  frames  as 
required.  The  following  diagrams  illustrate  the 
method: 


Les  cartes,  planches,  tableaux,  etc.,  peuvent  dtre 
filmds  i  des  taux  de  reduction  diffdrents. 
Lorsque  le  document  est  trop  grand  pour  dtre 
reproduit  en  un  seul  clich6,  il  est  film6  6  partir 
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5 

6 

MEKTAL   JCYOLUTIOJSr 


IN 


AKIMALS. 


^UG2 


MENTAL  EVOLUTION 
IN  ANIMALS. 


BY 


GEORGE  JOHN  ROMANES,  M.A.,  LL.D.,  F.R.S., 


ACTHOB  OF   "animal   INTKLLIGENCB. 


''"V^^^^^X 


\  r>  y 


WITH  A 


POSTHUMOUS   ESSAY   ON   INSTINCT. 


BT 


OHAELES  DARWIN,  M.A.,  LL.D.,  F.rv.S. 


NEW   YORK: 
D.  APPLETON   AND   COMPANY, 

78    FIFTH    AVENUE. 
1900. 


^UG  2  6  1966 


318940 


PREFACE. 


It  will  be  observed  that  the  title  of  this  volume  is  "  Mental 
Evolution  in  Animals."  The  reasons  which  have  led  me  to 
depart  from  my  intention  (as  expressed  in  the  Preface  of 
"  Animal  Intelligence")  to  devote  the  present  essay  to  mental 
evolution  in  man  as  well  as  in  animals,  are  given  in  the 
introductory  chapter. 

It  may  appear  that  in  the  following  pages  a  somewhat 
disproportionate  amount  of  space  has  been  allotted  to  the 
treatment  of  Instinct;  but,  looking  to  the  confusion  which 
prevails  with  reference  to  this  important  branch  of  psychology 
in  the  writings  of  our  leading  authorities,  I  have  deemed  it 
desirable  to  consider  the  subject  exhaustively. 

It  is,  I  think,  desirable  briefly  to  explain  the  circum- 
stances under  which  I  have  been  enabled  to  produce  so  much 
hitherto  unpublished  material  from  the  MSS  of  the  late 
Mr.  Darwin,  and  also  to  state  the  extent  to  which  I  have 
availed  myself  of  such  of  this  unpublished  material  as  came 
into  my  hands.  As  I  have  already  explained,  in  the  Preface 
of  "  Animal  Intelligence,"  Mr.  Darwin  himself  gave  me  all  his 
MSS  relating  to  psychological  subjects,  with  the  request  that 
I  should  publish  any  parts  of  them  that  I  chose  in  my  works 
on  Mental  Evolution.  But  after  his  death  I  felt  that  the  cir- 
cumstances with  reference  to  this  kind  oflFer  were  changed, 
and  that  I  should  scarcely  be  justified  in  appropriating  so 
much  material,  the  value  of  which  had  become  enhanced.  I 
therefore  published  at  the  Linnean  Society,  and  with  the 
consent  of  Mr.  Darwin's  family,  as  much  of  this  material  as 


PBEFACB. 


could  be  published  in  a  consecutive  form ;  this  is  the  chapter 
which  was  intended  for  the  "  Origin  of  Species,"  and  which, 
for  the  sake  of  reference,  I  have  added  as  an  Appendix  to  my 
present  work.  For  the  rest,  the  numerous  disjointed  para- 
graphs and  notes  which  I  found  among  the  MSS  I  have 
woven  into  the  text  of  this  book,  feeling  on  the  one  hand 
that  they  were  not  so  well  suited  to  appear  as  a  string  of 
disconnected  passages,  and  on  the  other  hand  that  it  was 
desirable  to  publish  them  somewhere.  I  have  gone  through 
all  the  MSS  carefully,  and  have  arranged  so  as  to  introduce 
every  passage  in  them  of  any  importance  which  I  find  to 
have  been  hitherto  unpublished.  In  no  case  have  I  found 
any  reason  to  suppress  a  passage,  so  that  the  quotations  which 
I  have  given  may  be  collectively  regarded  as  a  full  supple- 
mentary publication  of  all  that  Mr.  Darwin  has  written  in  the 
domain  of  psychology.  In  order  to  facilitate  reference,  I  have 
given  in  the  Index,  under  Mr.  Darwin's  name,  the  numbers  of 
all  the  pages  in  this  work  where  the  quotations  in  question 
occur. 

18,  CosywAXii  Tebbace, 

Beqbnx'b  Park,  London,  N.W., 
November,  1883. 


CONTENTS. 


Pbbfacb        1 

Inteodpctiow         5 

Chaptee      I.    The  Cbitkeion  of  Mixd       16 

„         II.    The  Steuctuee  and  Functions  of  Nebve-Tissce  24 

„        III.    The  Phtsioal  Basis  of  Mind        31 

„        IV.    The  Root-peinciples  op  Mind       47 

„  V.      EXPIANATION   OF   THE   DiAOEAU  63 

„        VI.    Consciousness 70 

„      VII.    Sensation  78 

„     VIII.    Pleasuees  and  Pains,  Memout,  and  Association 

OP  Ideas  103 

„        IX.    Peeception        123 

„         X.    Imagination       142 

„        XI.    Instinct 159 

„      XII.    Instinct  (continued). 

Origin  and  Development  of  Instincts  ..  ..  177 
„    XIII.    Instinct  (continued). 

Blended  Origin,  or  Plasticity  of  Instinct. .  . .  200 
„    XIV.    Instinct  (continued). 

Modes  in  which  Intelligence  determines  the  Varia- 
tion of  Instinct  in  Definite  Lines         . ,         . .       19 
„      XV.    Instinct  (continued). 

Domestication  .,         ,,         ',,         ,,         ,,     230 

„    XVI.    Instinct  (continued). 

Local  and  Specific  Varieties  of  Instinct   ..         .,     243 

„  XVII.    Instinct  (continued). 

Examination  of  the  Theories  of  other  Writers  on 
tlie  Evolution  of  Instinct,  with  a  General  Sum- 
mary of  the  Theory  here  Set  Forth     ..         ..     256 


^  CONTENTS. 

Chaptbb  XVIII.    lN8TiircT  (continued). 

Oa«e»  of  Special  Difflcultj  with  Regord  to  the 
Foregoing  Theory  of  the  Origin  and  Develop- 
ment of  InstinotB         273 

II  XIX.    Rbason  ,,         ,,         818 

n  XX.    Animal  Emotions,    and   Summabt   of    Intel*       • 

LEOTCAt  FaCCLTIBS  841 

Apmndix    „        863 


VAQM 


the 

op- 

•  • 

273 

•  t 

818 

•  • 

• 

841 

•  • 

863 

i2. 


49 

48 


47 


46 


45 


44 
43 


42 


41 


40 


39 


ir 


36 


3S 


34 


33 


32 


3' 


30 


PxoDUOTt  OF  Emotional  OivcLorMtNT. 


29 


W 


27 


26 


25 


24 


23 


22 


21 


20 


19 


«7 


16 


'S 


14 


13 


12 


II 


10 


Shame,  Kemorse,  JJeceitrulnus,  Liulicroiis. 


Revenge,  Rag^. 


Grief,  Hate,  Cruelty,  Benevolence. 


Kmtilation,  Pride,  Resentment,  Aesthetic  love  of  ornament.  Terror. 


Sympathy. 


Aflection. 


Jealousy,  Anger,  Play. 


Parental  aflection,  Social  feeiiags,  Sexual  selectioo,  Pugnacity,  Industry,  Curiosity. 


Sexual  emotions  without  sexual  selection. 


Surprise,  Fear. 


INTRODUCTION. 


In  the  family  of  the  sciences  Comparative  Psychology  may 
claim  nearest  kinship  with  Comparative  Anatomy ;  for  just 
as  the  latter  aims  at  a  scientific  comparison  of  the  bodily 
structures  of  organisms,  so  the  former  aims  at  a  similar  com- 
parison of  their  mental  structures .♦  Moreover,  in  the  one 
science  as  in  the  other,  the  first  object  is  to  analyze  all  the 
complex  structures  with  which  each  has  respectively  to  deal. 
When  this  analysis,  or  dissection,  has  been  completed  for  as 
great  a  number  of  cases  as  circumstances  permit,  the  next 
object  is  to  compare  with  one  another  all  the  structures  which 
have  been  thus  analyzed ;  and,  lastly,  the  results  of  such 
comparison  supply,  in  each  case  alike,  the  basis  for  the  final 
object  of  these  sciences,  which  is  that  of  classifying,  with 
reference  to  these  results,  all  the  structures  which  have  been 
thus  examined. 

In  actual  research  these  three  objects  are  prosecuted,  not 
successively,  but  simultaneously.  Thus  it  is  not  necessary 
in  either  case  that  the  final  object—that  of  classification- 
should  wait  for  its  commencement  upon  the  completion  of 
the  dissection  or  analysis  of  every  organism  or  every  mental 
structure  that  is  to  be  found  upon  the  earth.  On  the  con- 
trary, the  comparison  in  each  case  begins  with  the  facts  that 
are  first  found  to  be  comparable,  and  is  afterwards  pro- 
gressively extended  as  knowledge  of  additional  facts  becomes 
more  extensive. 

Now  each  of  the  three  objects  which  I  have  named  affords 

•  The  word  "structure"  is  used  in  a  metaphorical  sense  when  appUed  to 
xoind,  but  the  usage  is  convenient. 


6 


INTRODUCTION. 


in  its  pursuit  many  and  varied  points  of  interest,  which  are 
quite  distinct  from  any  interest  that  may  be  felt  in  the  attain- 
ment of  the  ultimate  end — Classification.  Thus,  for  example, 
the  study  of  the  human  hand  as  a  mechanism  has  an  interest 
apart  from  all  considerations  touching  the  comparison  of  its 
structure  with  that  of  the  corresponding  member  in  other 
animals ;  and,  similarly,  the  study  of  the  psychological  facul- 
•ties  in  any  given  animal  has  an  interest  apart  from  aU  con- 
siderations touching  their  comparison  with  the  corresponding 
faculties  in  other  animals.  Again,  just  as  the  comparison  of 
separate  bodily  members  throughout  the  animal  series  has  an 
interest  apart  from  any  question  concerning  the  classification 
of  animal  bodies  to  which  such  comparison  may  ultimately 
lead,  so  the  study  of  separate  psychical  faculties  throughout 
the  animal  series  (including,  of  course,  mankind)  has  an 
interest  quite  distinct  from  any  question  concerning  the 
classification  of  animal  minds  to  which  such  comparison  may 
ultimately  lead.  Lastly,  around  and  outside  all  the  objects 
of  these  sciences  as  such,  there  lies  the  broad  expanse  of 
General  Thought,  into  which  these  sciences,  in  all  their 
stages,  throw  out  branches  of  inference.  It  is  needless  to 
say  that  of  late  years  the  interest  with  which  the  unpre- 
cedented growth  of  these  branches  is  watched  has  become  so 
universal  and  intense,  that  it  may  be  said  largely  to  have 
absorbed  the  more  exclusive  sources  of  interest  which  I  have 
enumerated. 

With  the  view  of  furthering  these  various  lines  of  interest, 
I  have  undertaken  a  somewhat  laborious  enquiry,  part  of 
which  has  already  been  published  in  the  International 
Scientific  Series,  and  a  further  instalment  of  which  is  con- 
tained in  the  present  volume.  The  two  works,  therefore, 
"  Animal  Intelligence  "  and  "  Mental  Evolution  in  Animals," 
although  published  separately,  are  really  one ;  and  they  have 
been  divided  only  for  the  following  reasons.  In  the  first 
place,  to  have  produced  the  whole  as  one  volume  would  have 


INTRODUCTION.  *J 

been  to  present  a  book,  if  not  of  inconvenient  bulk,  at  least 
quite  out  of  keeping  with  the  size  of  all  the  other  books  in 
the  same  series.  Moreover,  the  subject-matter  of  each  work, 
although  intimately  related  to  that  of  the  other,  is  never- 
theless quite  distinct.  The  first  is  a  compendium  of  facts 
relating  to  Animal  Intelligence,  which,  while  necessary  as  a 
basis  for  the  present  essay,  is  in  itself  a  separate  and  distinct 
treatise,  intended  to  meet  the  interest  already  alluded  to  as 
attaching  to  this  subject  for  its  own  sake ;  while  tlie  second 
treatise,  although  based  upon  the  former,  has  to  deal  with  a 
wider  range  of  subject-matter. 

It  is  evident  that,  in  entering  upon  this  wider  field,  I  shall 
frequently  have  to  quit  the  narrower  limits  of  direct  obser- 
vation within  which  my  former  work  was  confined ;  and  it  is 
chieiiy  because  I  think  it  desirable  clearly  to  distinguish 
between  the  objects  o^  Comparative  Psychology  as  a  science, 
and  any  inferences  or  doctrines  which  may  be  connected  with 
its  study,  that  I  have  made  so  complete  a  partition  of  the 
facts  of  animal  intelligence  from  the  theories  which  I  believe 
these  facts  to  justify. 

So  much,  then,  for  the  reasons  which  have  led  to  the  form 
of  these  essays,  and  the  relations  which  I  intend  the  one  to 
bear  to  the  other.  I  may  now  say  a  few  words  to  indicate 
the  structure  and  scope  of  the  present  essay. 

Every  discussion  must  rest  on  some  basis  of  assumption  ; 
every  thesis  must  have  some  hypothesis.  The  hypothesis 
which  I  shall  take  is  that  of  the  truth  of  the  general  theory 
of  Evolution :  I  shall  assume  the  truth  of  this  theory  so  far 
as  I  feel  that  all  competent  persons  of  the  present  day  will 
be  prepared  to  allow  me.  I  must  therefore  first  define  what 
degree  of  latitude  I  suppose  to  be  thus  conceded. 

I  take  it  for  granted,  then,  that  all  my  readers  accept  the 
doctrine  of  Organic  Evolution,  or  the  belief  that  all  species  of 
plants  and  aniniels  have  had  a  derivative  mode  of  origin  by 
^^7-°^  ^^^^^'^i /''  ^^^^^'>  and,  moreover,  that  one  great  law  or 


8 


INTRODUCTION. 


method  of  the  process  has  been  natural  selection,  or  survival 
of  the  fittest.     If  anyone  grants  this  much,  I  further  assume 
that  he  must  concede  to  me  the  fact,  as  distinguished  from  the 
manner  and  history  of  Mental  Evolution,  throughout  the  whole 
range  of  the  animal  kingdom,  with  the  exception  of  man.     I 
assume  this  because  I  hold  that  if  the  doctrine  of  Organic 
Evolution  is   accepted,  it  carries  with  it,   as   a  necessary 
corollary,  the  doctrine  of  Mental  Evolution,  at  all  events  as 
far  as  the  brute  creation  is  concerned.     I'or  throughout  the 
brute  creation,  from  wholly  unintelligent  animals  to  the  most 
highly  intelligent,  we  can  trace  one  continuous  gradation;  so 
that  if  we  already  believe  that  all  specific  forms  of  animal 
life  have  had  a  derivative  origin,  we  cannot  refuse  to  believe 
that  all  the  mental   faculties  which   these  various  forms 
present  must  likewise  have  had  a  derivative  origin.     And,  as 
a  matter  of  fact,  we  do  not  find  anyone  so  unreasonable  as  to 
maintain,  or  even  to  suggest,  that  if  the  evidence  of  Organic 
Evolution  is  accepted,  the  evidence  of  Mental  Evolution, 
within  the  limits  which  I  have  named,  can  consistently  be 
rejected.     The  one  body  of  evidence  therefore  serves  as  a 
pedestal  to  the  other,  such  that  in  the  absence  of  the  former 
the  latter  would  have  no  locus  standi  (for  no  one  could  well 
dream  of  Mental  Evolution  were  it  not  for  the  evidence  of 
Organic  Evolution,  or  of  the  transmutation  of  species) ;  while 
the  presence  of  the  former  irresistibly  suggests  the  necessity 
of  the  latter,  as  the  logical  structure  for  the  support  of  which 
the  pedestal  is  what  it  is. 

It  will  be  observed  that  in  this  statement  of  the  case  I 
have  expressly  excluded  the  psychology  of  man,  as  being  a 
department  of  comparative  psychology  with  reference  to 
which  I  am  not  entitled  to  assume  the  principles  of  Evolu- 
tion. It  seems  needless  to  give  my  reasons  for  this  exclusion 
For  it  is  notorious  that  from  the  hour  when  Mr.  Darwin  and 
Mr.  Wallace  simultaneously  propounded  the  theory  which 
has  exerted  so  enormous  an  influence  on  the  thought  of  tha 


I! 


INTRODUCTION. 


9 


present  century,  the  difiference  between  the  views  of  these 
two  joint  originators  of  the  theory  has  since  been  shared  by 
the  ever-increasing  host  of  their  disciples.      We  all  know 
what  that  difference  is.     We  all  know  that  while  Mr.  Darwin 
believed  the  facts  of  human  psychology  to  admit  of  being 
explained  by  the  general  laws  of  Evolution,  Mr.  Wallace  does 
not  believe  these  facts  to  admit  of  being   thus  explained. 
Therefore,  while  the  followers  of  Mr.  Darwin  maintain  that 
all  organisms  whatsover  are   alike  products  of  a  natural 
genesis,  the  followers  of  Mr.  Wallace  maintain  that  a  distinct 
exception  must  be  made  to  this  general    atement  in  the  case 
of  the  human  organism ;  or  at  all  events  in  the  case  of  the 
human  mind.    Thus  it  is  that  the  great  school  of  evolutionists 
is  divided  into  two  sects ;  according  to  one  the  mind  of  man 
has  been  slowly  evolved  from  lower  types  of  psychical  exist- 
ence, and  according  to  the  other  the  mind  of  man,  not  having 
been  thus  evolved,  stands  apart,  sui  generis,  from  all  other 
types  of  such  existence. 

Now  assuredly  we  have  here  a  most  important  issue,  and 
as  it  is  one  the  discussion  of  which  will  constitute  a  large 
element  of  my  work,  it  is  perhaps  desirable  that  I  should 
state  at  the  outset  the  manner  in  which  I  propose  to  deal 
with  it. 

The  question,  then,  as  to  whether  or  not  human  intelli- 
gence has  been  evolved  from  animal  intelligence  can  only  be 
dealt  with  scientifically  by  comparing  the  one  with  the  other, 
in  order  to  ascertain  the  points  wherein  they  agree  and  the 
points  wherein  they  differ.  Now  there  can  be  no  doubt  that 
wlien  this  is  done,  the  difference  between  the  mental  faculties 
of  the  most  intelligent  animal  and  the  mental  faculties  of  the 
lowest  savage  is  seen  to  be  so  vast,  that  the  hypothesis  of 
their  being  so  nearly  allied  as  Mr.  Darwin's  teaching  implies, 
appears  at  first  sight  absurd.  And,  indeed,  it  is  not"  until  we 
have  become  convinced  that  the  tlieory  of  Evolution  can 
alone  afford  an  explanation  of  the  facts  of  human  anatomy 


10 


INTRODUCTION. 


that  we  are  prepared  to  seek  for  a  similar  explanation  of  the 
facts  of  human  psychology.  But  wide  as  is  the  difference 
between  the  mind  of  a  man  and  the  mind  of  a  brute,  we  must 
remember  that  the  question  is  one,  not  as  to  degree,  but  as  to 
kmd  ;  and  therefore  that  our  task,  as  serious  enquirers  after 
truth,  is  calmly  and  honestly  to  examine  the  character  of  the 
diff'erence  which  is  presented,  in  order  to  determine  whether 
It  IS  really  beyond  the  bounds  of  rational  credibility  that  the 
enormous  interval  which  now  separates  these  two  divisions  of 
mind  can  ever  have  been  bridged  over,  by  numberless  inter- 
mediate gradations,  during  the  untold  ages  of  the  past. 

While  writing  the  first  chapters  of  the  present  volume  I 
intended  that  the  latter  half  of  it  should  be  devoted  to  a  con- 
sideration of  this  question,  and  therefore  in  "Animal  Intelli- 
gence" I  said  that  such  would  be  the  case.     But  as  the 
work  proceeded  it  soon  became  evident  that  a  full  treat- 
ment of  this  question  would  require  more  space  than  could 
be  allowed  in  a  single  volume,  without  seriously  curtailing 
both  the  consideration  of  this  question  itself  and  also  that  of 
Mental  Evolution,  as  this  is  exhibited  in  the  animal  kingdom. 
I  therefore  determined  on  restricting  the  present  essay^'to  a 
consideration  of  Mental  Evolution  in  Animals,  and  on  reserv- 
ing for  subsequent  publication  all  the  material  which  I  have 
collected  bearing  on  Mental  Evolution  in  Man.     I  cannot 
yet  say  how  long  it  will  be  before  I  can  feel  that  I  am  justified 
in  publishing  my  researches  concerning  this  branch  of  my 
subject;  for  the  more  that  I  have  investigated  it,  the  more 
have  I  found  that  it  grows,  as  it  were,  in  three  dimensions— 
m  depth,  width,  and  complexity.     But  at  whatever  time  I 
shall  be  able  to  publish  the  third  and  final  instalment  of 
my  work,  it  will  of  course  rest  upon  the  basis  supplied  by 
the  present  essay,  as  this  rests  upon  the  basis  supplied  by 
the  previous  ona 

It  being  understood,   then,  that   the  present  essay  is 
restricted  to  a  consideration  of  Mental  Evolution  in  Animals 


INTRODUCTION, 


11 


I  should  like  to  have  it  also  understood  that  it  is  further 
restricted  to  the  psychology  as  distinguished  from  the  philo- 
sophy of  the  subject.    In  a  short  and  independent  essay 
published  elsewhere .♦  I  have  already  stated  my  views  con- 
cerning the  more  important  questions  of  philosophy  into 
which  the  subject-matter  of  psychology  is  so  apt  to  dip  •  but 
here  it  is  only  needful  to  emphasize  the  fact  that  these  two 
strata  of  thought,  although  assuredly  in  juxtaposition,  are 
no  less  assuredly  distinct.     My  present  enquiry  belongs  only 
to  the  upper  stratum,  or  to  the  science  of  psycholocry  as  dis- 
tinguished from  any  theory  of  knowledge.    I  am  in  no  wise 
concerned  with  "  the  transition  from  the  object  known  to  the 
knowing  subject,"  and  therefore  I  am  in  no  wise  concerned 
with  any  of  the  philosophical  theories  which  have  been  pro- 
pounded upon  this  matter.    In  other  words,  I  have  every- 
where  to  regard  mind  as  an  object  and  mental  modifications  as 
phenomena;  therefore  I  have  throughout  to  investigate  the 
process  of  Mental  Evolution  by  what  is  now  generally  and 
aptly  termed  the  historical  method.    I  cannot  too  strongly 
impress  upon  the  memory  of  those  who  from  previous  reading 
are  abie  to  appreciate  the  importance  of  the  distinction,  that 
I  thus  intend  everywhere  to  remain  within  the  borders  of 
psychology,  and  nowhere  to  trespass  upon  the  grounds  of 
philosophy.  ^ 

On  entering  so  wide  a  field  of  enquiry  as  that  whose  limits 
I  have  now  indicated,  it  is  indispensable  to  the  continuity  of 
advance  that  we  should  be  prepared,  where  needful,  to  supple- 
ment observation  with  hypothesis.  It  therefore  seems  desira- 
ble to  conclude  this  Introduction  with  a  few  words  both  to 
explain  and  to  justify  the  method  which  in  this  matter  I 
intend  to  follow. 

It  has  already  been  stated  that  the  sole  object  of  this 
work  is  that  of  tracing,  in  as  scientific  a  manner  as  possible 
the  probable  history  of  Mental  Evolution,  and  therefore,  of 

■^  Nineteenth  Centurif,  December,  1882, 


r 


.?  I 


12 


INTRODUCTION. 


course,  of  enquiring  into  the  causes  which  have  determined  it. 
So  far  as  observation  is  available  to  guide  us  in  this  enquiry, 
I  shall  resort  to  no  other  assistance.  Where,  however,  from 
the  nature  of  the  case,  observation  fails  us,  I  shall  proceed  to 
inference.  But  though  I  shall  use  this  method  as  sparingly 
as  possible,  I  am  aware  that  criticism  will  often  find  valid 
ground  to  object — '  It  is  all  very  well  to  map  out  the  sup- 
posed genesis  of  the  various  mental  faculties  in  this  way,  but 
we  require  some  definite  experimental  or  historical  proof  that 
the  genesis  in  question  actually  did  take  place  in  the  order 
and  manner  that  you  infer,' 

Now,  in  answer  to  this  objection,  I  have  only  to  say  that 
no  one  can  have  a  more  lively  appreciation  than  myself  of 
the  supreme  importance  of  experimental  or  historical  veri- 
fication, in  all  cases  where  the  possibility  of  such  verification 
is  attainable.    But  in  cases  where  such  verification  is  not 
attainable,  what  are  we  to  do  ?    We  may  clearly  do  either  of 
two  things.    We  may  either  neglect  to  investigate  the  sub- 
ject at  all,  or  we  may  Jo  our  best  to  investigate  it  by  employ- 
ing the  only  means  of  investigation  which  are  at  our  disposal. 
Of  these  two  courses  there  can  be  no  doubt  which  is  the  one 
that  the  scientific  spirit  prompts.    The  true  scientific  spirit 
desires  to  examine  everything,  and  if  in  any  case  it  is  refused 
the  best  class  of  instruments  wherewith    to   conduct  the 
examination,  it  will  adopt  the  next  best  that  are  available. 
In  such  cases  science  clearly  cannot  be  forwarded  by  neglect- 
ing to  use  these  instruments,  while  her  cause  may  be  greatly 
advanced  by  using  them  with  care.    This  is  proved  by  the 
fact  that,  in  the  science  of  psychology,  nearly  all  the  con- 
siderable advances  which  have  been  made,  have  been  made, 
not  by  experiment,  but  by  observing  mental  phenomena  and 
reasoning  from  these  phenomena  deductively.    In  such  cases, 
therefore,  the  true  scientific  spirit  prompts  us,  not  to  throw 
away  deductive  reasoning  where  it  is  so  frequently  the  only 


INTRODUCTION. 


13 


instrument  available,  but  rather  to  carry  it  with  us,  and  to 
use  it  as  not  abusing  it. 

And  this,  as  I  have  said,  is  what  I  shall  endeavour  to  do. 
No  one  can  regret  more  than  myself  that  the  most  interesting 
of  all  regions  of  scientific  enquiry  should  happen  to  be  the 
one  in  which  experiment,  or  inductive  verification,  is  least 
of  all  applicable ;  but  such  being  the  case,  we  must  take  the 
case  as  we  find  it,  use  deductive  reasoning  where  we  clearly 
see  that  it  is  the  only  instrument  available,  but  use  it  to  as 
limited  an  extent  as  the  nature  of  our  subject  permits. 


|l         !i 


MENTAL  EVOLUTION  IN  ANIMALS. 


CHAPTER  I. 


The  Criterion  of  Mind. 


The  subject  of  our  enquiry  being  Mental  Evolution,  it  is 
desirable  to  begin  by  understanding  clearly  what  we  mean  by 
Mind,*  and  then  defining  the  conditions  under  which  known 
Mind  is  invariably  found  to  occur.  In  this  chapter,  therefore, 
I  shall  deal  with  what  I  take  to  be  the  Criterion  of  Mind, 
and  shall  then  pass  on  in  the  next  chapter  to  a  consideration 
of  the  objective  conditions  under  which  alone  Mind  is 
observed  to  exist. 

It  is  obvious,  then,  to  start  with,  that  by  Mind  we  may 
mean  two  very  different  things,  according  as  we  contemplate 
it  in  our  own  individual  selves,  or  as  manifested  by  other 
beings.  For  if  I  contemplate  my  own  mind,  I  have  an  imme- 
diate cognizance  of  a  certain  flow  of  thoughts  and  feelings, 
which  are  the  most  ultimate  things — and,  indeed,  the  only 
things — of  which  I  am  cognizant.  But  if  I  contemplate 
Mind  in  other  persons  or  organisms,  I  can  have  no  such 
immediate  cognizance  of  their  thoughts  and  feelings;  I  can 
only  infer  the  existence  of  such  thoughts  and  feelings  from 
the  activities  of  the  persons  or  organisms  which  appear  to 
manifest  them.  Thus  it  is  that  by  Mind  we  may  mean 
either  that  which  is  subjective  or  that  which  is  objective. 
Now  throughout  the  present  work  we  shall  have  to  consider 
Mind  as  an  object ;  and  therefore  it  is  well  to  remember  that 
our  only  instrument  of  analysis  is  the  observation  of  activities 

•  It  was  necessary  in  my  work  on  Animal  Intelligence  briefly  to  touch 
on  this  question  j  therefore  the  parts  of  the  analysis  which  are  common  to 
the  two  works  I  shall  render  as  much  as  pobsible  in  the  same  words. 


16 


MENTAL  EVOLUTION  IN  ANniALS. 


which  we  infer  to  be  prompted  by,  or  associated  with,  mental 
antecedents  or  accompaniments  analogous  to  those  of  which 
we  are  directly  conscious  in  our  own  subjective  experience. 
That  is  to  say,  starting  from  what  I  know  subjectively  of  the 
operations  of  my  own  individual  mind,  and  of  tlie  activi- 
ties wliicH  in  my  own  organism  these  operations  seem  to 
prompt,  I  proceed  by  analogy  to  infer  from  the  observable 
activities  displayed  by  other  organisms,  the  ftict  that  certain 
mental  operauions  underlie  or  accompany  these  activities. 

From  this  statement  of  the  case  it  will  be  apparent  tliat 
our  knowledge  of  mental  activities  in  any  organism  other 
than  our  own  is  neither  subjective  nor  objective.     That  it  -s 
not  subjective  I  need  not  wait  to  show.     That  it  is   not 
objective  may  be  rendered  obvious  by  a  few  moments'  reflec- 
tion. ^  For  it  is  evident  that  mental  aciivities    in    otlier 
organisms  can  never  be  to  us  objects  of  direct  knowledge ;  as 
I  have  just  said,  we  can  only  infer  their  existence  from  the 
objective  sources  supplied  by  observable  activities  of  such 
organisms.     Therefore  all  our  knowledge  of  mental  activities 
other  than  our  own  really  consists  of  an  inferential  inter- 
pretation   of    bodily    act'vities — this    interpretation    being 
founded  on  our  subjective  knowledge  of  our  own  mental 
activities.     By  inference  we  project,  as  it  were,  the  known 
patterns  of  our  own  mental  chromograph  on  what  is  to  us 
the  otherwise  blank  screen  ox  another  mind;  and  our  only 
knowledge  of  the  processes  there  taking  place  is  really  due 
to  such  a  projection  of  our  own  subjectively.     This  matter 
has  been  well  and  clearly  presented  by  the  late  Professor 
Clifford,  who  has  coined  the  exceedingly  appropriate  term 
eject  (in  contradistinction  to  subject  and  object),  whereby  to 
designate  the  distinctive  character  of  a  mind  (or  mental  pro- 
cess) other  than  our  own  in  its  relation  to  our  own.     I  shall 
therefore  adopt  this  convenient  term,  and  speak  of  all  our 
possible  knowledge  of  other  minds  as  ejective. 

Now  in  this  necessarily  ejective  method  of  enquiry,  what 
is  the  kind  of  activities  that  we  are  entitled  to  regard  as 
indicative  of  ]\Iind  ?  I  certainly  do  not  so  regard  the  flowing 
of  a  river  or  the  blowing  of  a  wind.  Why  ?  First,  because 
the  subjects  are  too  remote  in  kind  from  my  own  organism  to 
admit  of  my  drawing  any  reasonable  analogy  between  them 
and  it;  and,  secondly,  because  the  activities  which  they 
present  are  invariably  of  the  same  kind  under  the  same  cir- 


THE  CRITERION  OP  MIND.  ^f^ 

Consciousness.  In  other  wor^^^^^  L^.  'Tv  "^^^^  ^'  «"«»^- 
satisfied  before  wreven  Teain  f^-  "'^'^'""r^'l"'^^  ^«  be 
activities  are  indicat  ^of Xd  th?^fr  \'^''  '^'''''''^^' 
played  by  a  livino^  or^nism  «..!%?    ^"^^^^V^^^  must  be  dis- 

be  taken  as  the  criterion  of  consciousness  ?  S  hi  .  "i''  ^^ 
criterion  is  either  needful  or  possible  Z I  ^"^J^^^^^ely,  no 
nothing  can  be  more  ultlm^tP  £1  '  *°  '"®'  individually, 
and,  th-erefore,  my  conscbtness  cann"ot'"aLT  r^'^'"""^^^' 
having  a  claim  to  a  higher  ceStv  P^  ?^  7 ^^^^^ 
such  criterion  is  required  and  ^  ^"v  '  ^^J^^^^^^^ly^  some 
come  within  the  te/i^torv  of  «  I  ^  ^°^^sciousness  cannot 
only  appreciate  ?he  lattr  th/oiK^^^^^^^^^  consciousness,  I  can 
-these  ambassadors  beTnarfV^^  ^^'^'^  °^  ambassadors 
the  observable  ^o^ittetlf ::  l^^^^^^^ 
therefore,  is,  What  acfiviHflr^?  "  •  ^^?  "^^^  question, 

as  indicative  of  fnsc  ousnS  '^Cr''''' .T  ''  ^'  '^^'^ 
readily  is,-All  aSirth.f  ^"'T' ^^^^  ^^"^««  "^ost 
vvhereverwCaliSnL  ^'^  indicative  of  Choice; 
tional  choice  we  XfnSr^^^^  exerting  inten-' 

therefore,  that  the  omanil  T^^       ''  conscious  choice,  and, 

shows  that  t4  ans:S™not  do'  rtl  -^^  f^^'^ 
whether  there  is  any  minr  wS.^  /  lu  '  '"^^"^^  ''"^  disputing 

choice,  physiology,l^wTsh.  rl-n  ,f'  ^Tf  °^  ^°"«^^°"^ 
lirm  in  denying  that  aTlannll^^^  I  ^''"-"'f  *^  "^'^P^^^-  ^^  ^ery 
host  of  reilex  actions  t  SvpH  V  ''!?.  "^"^  *°  "^^"^-  ^he 
in  view  of  such  ZlnientallnTr'^  '^''  proposition,  and, 
adjustments,  we  hnrtScL  tv  1^  apparently  intentional 
element  as  real  or  fictiSr  ThI  \  T'  ^''^  ^^  ^^'^  ^^^ice- 
whether  the  adjTs  ments  1--^^^^^  '''  ^'''^'  ^'  ^"  '^^ 

under  the  samTc  rc^2aST«l  "'1  l"''''^"^''^  ^'^^  ^''^"^'^ 
tinction  between  ad  Wivo  stimulation.     The  only  dis- 

and  adjustivrmovein  r^^  ''  '''^'^  action, 

consists  in  the  fSer  L^nT^    '"^-^r"'"^'^ 
within  the  nervous  system  hpt"°  ^'^  '"^''^^'^^  mechanisms 
^«^-^ic.^«.  adjiiS  Totme^s^  ^^^  ^^  ^^^^^ 

stimulations,  while  thi  Sr  !      "  Response   to  ii;«r^^•cM/ar 


fi! 


18 


MENTAL  EVOLUTION  IN  ANIMALS. 


of  a  machine  under  the  manipulations  of  an  operator :  when 
certain  springs  of  action  are  touched  by  certain  stimuli,  the 
whole  machine  is  thrown  into  appropriate  action ;  there  is  no 
room  for  choice,  there  is  no  room  for  uncertainty ;  but,  as 
surely  as  any  of  these  inherited  mechanisms  is  affected  by 
the  stimulus  with  reference  to  which  it  has  been  constructed 
to  act,  so  surely  will  it  act  in  precisely  th^  same  way  as  it 
always  has  acted.  But  the  case  with  conscious  mental  adjust- 
ment is  quite  different.  For,  without  going  into  the  question 
concerning  the  relation  of  Body  and  Mind,  or  waiting  to  ask 
whether  cases  of  mental  adjustment  are  not  really  quite  as 
mechanical  in  the  sense  of  being  the  necessary  result  or 
correlative  of  a  chain  of  psychical  sequences  due  to  a  physical 
stimulation,  it  is  enough  to  point  to  the  variable  and  incalcu- 
lable character  of  mental  adjustments  as  distinguished  from 
the  constant  and  foreseeable  character  of  reflex  adjustments. 
All,  in  fact,  that  in  an  objective  sense  we  can  mean  by  a 
mental  adjustment,  is  an  adjustment  of  a  kind  that  has  not 
been  definitely  fixed  by  heredity  as  the  only  adjustment 
possible  in  the  given  circumstances  of  stimulation.  For,  were 
there  no  alternative  of  adjustment,  the  case,  in  an  animal  at 
least,  would  be  indistinguishable  from  one  of  reflex  action. 

It  is,  then,  adaptive  action  by  a  living  organism  in  cases 
where  the  inherited  machinery  of  the  nervous  system  does 
not  furnish  data  for  our  prevision  of  what  the  adaptive  action 
must  necessarily  be — it  is  only  in  such  cases  that  we  recog- 
nize the  element  of  mind.  In  other  words,  ejectively  con- 
sidered, the  distinctive  element  of  mind  is  consciousness,  the 
test  of  consciousness  is  the  presence  of  choice,  and  the 
evidence  of  choice  is  the  antecedent  uncertainty  of  adjustive 
action  between  two  or  more  alternatives.  To  this  analysis  it 
is,  however,  needful  to  add  that,  although  our  only  criterion 
of  mind  is  antecedent  uncertainty  of  adjustive  action,  it  does 
not  follow  that  all  adjustive  action  in  which  mind  is  con- 
cerned should  be  of  an  antecedently  uncertain  character ;  or, 
which  is  the  same  thing,  that  because  some  such  action  may 
be  of  an  antecedently  certain  character,  we  should  on  this 
account  regard  it  as  non-mental.  Many  adjustive  actions 
which  we  recognize  as  mental  are,  nevertheless,  seen  before- 
hand to  be,  under  the  given  circumstances,  inevitable ;  but; 
analysis  would  show  that  such  is  only  the  case  when  we  have 
in  view  agents  whom  we  already,  and  from  independent 
evidence,  regard  as  mental. 


THE   CRITERION  OP  MIND. 


-^19 


Tn  positing  the  evidence  of  Choice  as  my  objective  (or 
ejective)  criterion  of  Mind,  I  do  not  think  it  necessary  to 
enter  into  any  elaborate  analysis  of  what  constitutes  this 
evidence.     In  a  subsequent  chanter  I  shall  treat  fully  of 
what  I  call  the  physiology  or  objective  aspect  of  choice ;  and 
then  it  will  be  seen  that  from  the  gradual  manner  in  which 
choice,  or  the  mind-element,    arises,  it   is  not  practically 
possible  to  draw  a  definite  line  of   demarcation   between 
choosing  and  non-choosing  agents.     Therefore,  at  this  stage 
of  the  enquiry  I  prefer  to  rest  in  the  ordinary  acceptation  of 
the  term,  as  implying  a  distinction  which  common  sense  has 
always  drawn,  and  probably  always  will  draw,  between  mental 
and  non-mental  agents.     It  cannot  be  correctly  said  that  a 
river  chooses  the  course  of  its  flow,  or  that  the  earth  chooses 
an  ellipse  wherein  to  revolve  round  the  sun.    And  similarly, 
however  complex  the  operations  may  be  of  an  agent  recog- 
nized as  non-mental— such,  for  instance,  as  those  of  a  calcu- 
lating machine— or  however  impossible  it  may  be  to  predict 
the  result  of  its  actions,  we  never  say  that  such  operations  or 
actions  are  due  to  choice ;  we  reserve  this  term  for  operations 
or  actions,  however  simple  and  however  easily  the  result  may 
be  foreseen,  which  are  performed,  either  by  agents  who  in 
virtue  of  the  non-mechanical  nature  of  these  actions  prove 
themselves  to  be  mental,  or  by  agents  already  recognized  as 
mental— i.e.,  by  agents  who  have  already  proved  themselves 
to  be  mental  by  performing  other  actions  of  such  a  non- 
mechanical  or  unforeseeable  nature  as  we  feel  assured  can 
only  be  attributed  to  choice.    And  there  can  be  no  reasonable 
doubt  that  this  common-sense  distinction  between  choosing 
and  non-choosing  agents  is  a  valid  one.     Although  it  may  be 
difficult  or  impossible,  in  particular  cases,  to  decide  to  which 
of  the  two  categories  this  or  that  being  should  be  assigned, 
this  difficulty  does  not  aftect  the  validity  of  the  classification 
—any  more,  for  instance,  than   the  difficulty  of   deciding 
whether  Limulus  should  be  classified  with  the  crabs  or  with 
the  scorpions  affects  the  validity  of  the  classification  which 
marks  off  the  group  Crustacea  from  the  group  Arachnida. 
The  point  is  that,    notwithstanding  special  difficulties  in 
assigning  this  or  that  being  to  one  or  the  other  class,  the 
psychological     classification    which    I    advocate    resembles 
the  zoological  classification  which  I  have  cited  ;  it  is  a  valid 
classification,  inasmuch  as  it  recognizes  a  distinction  where 


20 


MENTAL  EVOLUTION  IN  ANIMALS. 


take' the  mo^i^  T'"^?^- ''  ^^^ti^.-^^h-    For  even  if  we 

cer  a  ^L  oL  ^ntemgence  e.ists,  and  that  prior  o 

cercam  act  ions  it  is  always  affected  n  certain  wavs     ThorP 

nptV     '"-i  ^^«"PPo«e  that  the  state  of  thTn %  is   so  to 

proceed  without,  and  those  that  proceed  with  this  remaTkaWe 
jectivity  are  lacts  at  any  rate  no  Ipss  rpnl  fiiov.  fi,^        c 

atdS'n  ''  '^  """f''^^'  -meV?rellt   r™  iu'variaV/ 
and  faithful  y  mirrored  in  those  of  the  former  such Theno 
mena,  for  this  reason  alone,  deserve  to  he  nln^.,  i„  „  j- .™  I 
scientific  category,  even  though  it  we,^  pro^uhet™ 

connTitLtrSdrrd's,  i^L  roXna^!^t 

a  e  SmpaSedTvXr ''■"'""'J™  ^''''^*'"  activities  which 

we%rsSTrfnott':fcrpa';,ivirs  r^'i^i/oC  ^r 

tSrthl  tm'cT  "^'^^r  to"co!»i;^«Sn^o" 
acton    areTent^Z;  "S™'!,*"'  »<*  able  to  c;«<„»  their 

detZine?hStce        "'  ''"'  '"^'^^  "'«  »"™''  «■'>-!' 
gence .  —  it  is,  then,  adaptive  action  by  a  livino-  oranm-^^m 

rs'nTtaistdSt''''  """"'"^'^ "' "-  Suri  s 

uues  not  lurnish  data  for  our  prevision  of  what  the  adantivp 
action  must  necessarily  be-it  is  only  here  th 't  we  recoSe 

h^Vforwhic-'t""  ''  "^".'"     ^'^^   criteria;  ^r'm?:^ 
tneretore,   whit  i  I  propose,  and  to  which   I   shall   adhere 

throughou    the  present  volume,   is   as  follows --Does   the 
organism  learn  to  make  new  adjustments,  or  to  modify  old 


THE  CRITERION  OP  MIND. 


21 


ones,  m  accordance  with  the  results  of  its  own  individual 
experience  ?  _  If  it  does  so,  the  fact  cannot  be  merely  due  to 
reflex  action  m  the  sense  above  described ;  for  it  is  impossible 
that  heredity  can  have  provided  in  advance  for  innovations 
upon  or  alterations  of  its  machinery  durin.r  the  lifetime  of  a 
particular  individual," 

Two   points    have  to  be  observed  with  regard  to  this 
criterion,  in  whichever  verbal  form  we  may  choose  to  express 
it.     The  first  is  that  it  is  not  rigidly  exclusive  either,  on  the 
one  hand,  of  a  possibly  mental  character  in  apparently  non- 
niental  adjustments,  or,  conversely,  of  a  possibly  non-mental 
character  in  apparently  mental  adjustments.     For  it  is  certain 
that  failure  to  learn  by  individual  experience  is  not  always 
conclusive  evidence  against  the  existence  of  mind;    such 
failure  may  arise  merely  from  an  imperfection  of  menify  or 
from  there  not  being  enour/h  of  the  mind-element  present  to 
make  the  adjustments  needful  to  meet  the  novel  circum- 
stances.    Conversely,  it  is  no  less  certain  that  some  parts  of 
our  own  nervous  system,  which  are  not  concerned  in  the 
phenomena  of  consciousness,  are  nevertheless  able  in  some 
measure  to  learn  by  individual  experience.      The  nervous 
apparatus  of  the  stomach,   for  instance,  is   able  in  so  con- 
siderable a  degree  to  adapt  the  movements  of  that  or^an  to 
the  requirements  of  its  individual  experience,  that  were  the 
organ  an  organism  we  might  be  in  danger  of  regardintr  it  as 
dimly  intelligent.     Still  there  is  no  evidence  to  show  that 
non-mental  agents  are  ever  able  in  any  considerable  measure 
thus  to  simulate  the  adjustments  performed  by  mental  ones  • 
and  therefore  our  criterion,  in  its  practical  application,  has 
rather  to  be  guarded  against  the  opposite  danger  of  denyinr^ 
the  presence  of  mind  to  agents  that  are  really  mental     For 
as  I  observed  in  "Animal  Intelligence,"  "it  is  clear  that  lon^ 
before  mind  has  advanced  sufficiently  far  in  the  scale  of 
development  to  become  amenable  to  the  test  in  question,  it 
has  probably  begun  to  dawn  as  nascent  subjectivity.     In 
.  other  words,  because  a  lowly  organized  animal  does  not  learn 
by  Its  own  individual  experience,  we  may  not  therefore  con- 
clude that  m  performing  its  natural  or  ancestral  adaptations 
to  anpropiate  stimuli,  consciousness,  or  the  mind-element  is 
wholly  absent ;  we  can  only  say  that  this  element,  if  present 
reveals  no  evidence  of  the  fact.     But,  on  the  other  hand,  if  a 
lowly  organized  animal  does   learn   by  its  own   individual 


22 


MENTAL  EVOLUTION  IN  ANIMALS. 


pi       i 


experience,  we  are  in  possession  of  the  best  available  evi- 
dence of  conscious  memory  leading  to  intentional  adaptation. 
Therefore,  our  criterion  applies  to  the  upper  limit  of  non- 
mental  action,  not  to  the  lower  limit  of  mental." 

Or,  again  adopting  the  convenient  terminology  of  Clifford, 
we  must  always  remember  that  we  can  never  know  the  mental 
states  of  any  mental  beings  other  than  ourselves  as  objects ; 
we  can  only  know  them  as  ejects,  or  as  ideal  projections  of  our 
own  mental  states.     And  it  is  from  this  broad  fact  of  psycho- 
logy that  the  difficulty  arises  in  applying  our  criterion  of 
mind  to  particular  cases — especially  among  the  lower  animals. 
For  if  the  evidence  of  mind,  or  of  being  capable  of  choice, 
must  thus  always  be  ejective  as  distinguished  from  objective, 
it  is  clear  that  the  cogency  of  the  evidence  must  diminish  as 
we  recede  from  minds  inferred  to  be  like  our  own,  towards 
minds  inferred  to  be  not  so  like  our  own,  passing  in  a  gradual 
series  into  not-minds.     Or,  otherwise  stated,  although   the 
evidence  derived  from  ejects  is  practically  regarded  a's  good 
in  the  case  of  mental  organizations  inferred  to  be  closely 
analogous  to  our  own,  this  evidence  clearly  ceases  to  be  trust- 
worthy in  the  ratio  in  which  the  analogy  fails  :  so  that  when 
we  come  to  the  case  of  very  low  animals — where  the  analogy 
is  least — we  feel  uncertain  whether  or  not  to  ascribe  to  them 
any  ejective  existence.     But  I  must  again  insist  that  this 
fact— which  springs  immediately  out  of   the  fundamental 
isolation  of  the  individual  mind— is  no  argument  against  my 
criterion  of  mind  as  the  best  criterion  available ;  it  tends, 
indeed,  to  show  that  no  better  criterion  can  be  found,  for  it 
shows  the  hopelessness  of  seeking  such. 

The  other  point  which  has  to  be  noted  with  regard  to  this 
criterion  is  as  follows.    I  again  quote  from  "  Animal  Intelli- 


gence :  — 


"  Of  course  to  the  sceptic  this  criterion  may  appear  un- 
satisfactory, since  it  depends,  not  on  direct  knowledge,  but 
on  inference.  Here,  however,  it  seems  enough  to  point  out, 
as  already  observed,  that  it  is  the  best  criterion  available ; 
and,  further,  that  scepticism  of  this  kind  is  logically  bound 
to  deny  evidence  of  mind,  not  only  in  the  case  of  the  lower 
animals,  but  also  in  that  of  the  higher,  and  even  in  that  of 
men  other  than  the  sceptic  himself.  For  all  objections  which 
could  apply  to  the  use  of  this  criterion  of  mind  in  the  animal 
kmgdom,  would  apply  with  equal  force  to  the  evidence  of  any 


THE  CRITERION  OF  MIND. 


23 


mind  other  than  that  of  the  iaiividual  objector.  This  is 
obvious,  because,  as  I  have  already  observed,  the  only  evi- 
dence we  can  have  of  objective  mind  is  that  which  is 
furnished  by  objective  activities  ;  and,  as  the  subjective  mind 
can  never  become  assimilated  with  the  objective  so  as  to  learn 
by  direct  feeling  the  mental  processes  which  there  accompany 
the  objective  activities,  it  is  clearly  impossible  to  satisfy  any 
one  who  may  choose  to  doubt  the  validity  of  inference,  that 
in  any  case,  other  than  his  own,  mental  processes  ever  do 
accompany  objective  activities. 

"  Thus  it  is  that  philosophy  can  supply  no  demonstrative 
refutation  of  idealism,  even  of  the  most  extravagant  forrri. 
Common-sense,  however,  universally  feels  that  analogy  is 
here  a  safer  guide  to  truth  than  the  sceptical  demand  for 
impossible  evidence;  so  that  if  the  objective  existence  of 
other  organisms  and  their  activities  is  granted — without 
which  postulate  comparative  psychology,  like  all  the  other 
sciences,  would  be  an  unsubstantial  dream— common  sense 
will  always  and  without  question  conclude  that  the  activities 
of  organisms  other  than  our  own,  when  analogous  to  those 
activities  of  our  own  which  we  know  to  be  accompanied  by 
certain  mental  states,  are  in  them  accompanied  by  analogous 
mental  states." 


r 


24 


MENTAL  EVOLUTION  IN  ANIMALS. 


CHAPTER  II. 

The  Structure  and  Functions  of  Nerve-Tissue. 

Having  thus  arrived  at  the  best  available  Criterion  of  Mind 
considered  as  an  eject,  we  have  now  to  pass  on  to  the  topic 
which  has  already  been  propounded,  viz.,  to  a  consideration 
ot  the  objective  conditions  under  which  known  mind  is  in- 
variably found  to  occur. 

Mind  then,  so  far  as  human  experience  extends,  is  only 
certainly  known  to  occur  in  association  with  living  organisms 
and,  still  more  particularly,  in  association  with  a  peculiar 
kind  of  tissue  which  does  not  occur  in  all  organisms,  and  even 
in  those  in  which  it  does  occur  never  constitutes  more  than 
an  exceedingly  small  percentage  of  their  bulk.    This  peculiar 
tissue,  so  sparingly  distributed  through  the  animal  kinr^dom 
and  presenting  the  unique  characteristic  of  being  associated 
with  mind,  IS,  of  course,  the  nervous  tissue.     It  therefore 
devolves  upon  us,  first  of  all,  to  contemplate  the  structure 
and  the  functions  of  this  tissue,  as  far  as  it  is  needful  for  the 
purposes  of  our  subsequent  discussion  that  these  should  be 
clearly  understood. 

Throughout  the  animal  kingdom  nerve-tissue  is  invariably 
present  in  aU  species  whose  zoological  position  is  not  below 
that  of  the  Hydrozoa.  The  lowest  animals  in  which  it  has 
hitherto  been  detected  are  the  Medusa,  or  jelly-fishes,  and 
from  them  upwards  its  occurrence  is,  as  I  have  said,  invari- 
able. Wherever  it  does  occur  its  fundamental  structure  is 
very  much  the  same,  so  that  whether  we  meet  with  nerve- 
tissue  m  a  jelly-fish,  an  oyster,  an  insect,  a  bird,  or  a  man, 
we  have  no  difticulty  in  recognizing  its  structural  units  as 
everywhere  more  or  less  similar.  These  structural  units  are 
microscopical  cells  and  microscopical  fibres.     (Figs.  1  2 ) 

Ihe  fibres  proceed  to  and  from  the  cells,  so  servin"  to 


THE  STRUCTURE  AND  FUNCTIONS  OF  NERVE-TISSUE.       25 


PiQ.  1.— Motor  Nerve  Cells  connected  by 
intercellular  proceBses  (b,  b),  and  giving 
origin  to  outgoing  fibres  (c,  c,  c,  and  a). 
4.  Multipolar  cell  containing  much  pig- 
ment around  nucleus.  Diagrammatic, 
(Vogt.) 


Fio.  2.— Multipolar  Ganglion  Cell  from 
anterior  grey  matter  of  Spinal  Cord 
of  Ox.  a,  Axis  cylinder  procesr :  i, 
branched  processes,  magnified  IBO  dia- 
meters.    (Deitera.) 


connect  the  cells  with  one  another,  and  also  with  distant 
parts  of  the  animal  body.  The  function  of  the  fibres  is  that 
of  conducting  stimuli  or  impressions  (represented  by  mole- 
cular or  invisible  movements)  to  and  from  the  nerve-cells, 
while  the  function  of  the  cells  is  that  of  originating  those  of 
the  impressions  which  are  conducted  by  the  fibres  outwards. 
Those  of  the  impressions  which  are  conducted  by  the  fibres 
inwards,  or  towards  the  cells,  are  originated  by  stimuli  affecting 
tlie  nerve-fibre  in  any  part  of  its  length ;  such  stimuli  may 
be  contact  with  other  bodies  or  pressure  arising  therefrom 
(mechanical  stimuli),  sudden  elevations  of  temperature  (ther- 
mal stimuli),  moleoular  changes  in  the  nerve-substance  pro- 


'4 


m 


26 


MENTAL  EVOLUTION  IN  ANIMALS. 


duced  by  irritants  (chemical  stimuli),  effects  of  electrical 
disturbance  (electrical  stimuli),  or  lastly,  the  passage  of  a 
molecular  disturbance  from  any  other  nerve-fibre  with  which 
the  one  in  question  may  be  connected. 

Nerve-cells  are  usually  found  collected  together  in  aggre- 
gates which  are  called  ganglia,  to  and  from  which  Tar^e 
bundles  of  nerve-fibres  come  and  go.  Tliese  rope-like 
clusters  of  nerve-fibres  constitute  the  white  threads  and 
strings  which  we  recognize  as  nerves  when  we  dissect  an 
animal.  (See  Fig.  3.)  Tiie  relation  of  the  clusters  of 
fibres  to  the  cluster  of  cells  is  now  such  as  to  supply  the 
anatomical  condition  to  the  performance  of  a  physiological 


FlQ.  3.— SmaU  Sympathetic  Ganglion  (hnman)  with  Multipolar 
Cells.    Magnified  about  400  diameters.     (Leydig.) 

process,  which  is  termed  Eeflex  Action.  If  we  suppose  the 
lett-hand  bundle  of  fibres  represented  in  the  woodcut  to  be 
prolonged  and  to  terminate  in  a  sensory  surface  while 
the  other  three  bundles,  when  likewise  prolonged,  terminate 
m  a  group  of  muscles,  then  a  stimulus  falling  upon  the 
sensory  surface  would  cause  a  molecular  disturbance  to  travel 
along  the  left-hand  or  in-going  nerve  to  tlie  ganglion-  on 
reaching  the  ganglion  this  disturbance  would  cause  'the 
ganglion  to  discharge  its  influence  into  the  right-hand  or  out- 
gwng  nerves,  which  would  then  conduct  this  disturbance  into 
the  group  of  muscles  and  cause  them  to  contract.  This  pro- 
cess 18  called  reflex-action,  because  the  original  stimulus 
tailing  upon  the  sensory  surface  does  not  pass  in  a  direct  line 


THE  STRUCTURE  AND  FUNCTIONS  OP  NERVE-TISSUE.       27 


to  its  destination  in  the  muscles,  but  passes  fir=(t  to  the 
ganglion,  and  is  thence  reflected  from  the  sensory  surface  to 
the  muscles.*  This,  which  at  first  sight  appears  a  round- 
about or  cumbrous  sort  of  process,  is  really  the  most  economic 
that  is  available.  For  we  must  remember  the  enormous 
number  and  complexity  of  the  stimuli  to  which  all  the  higher 
animals  are  perpetually  exposed,  and  the  consequent  neces- 
sity that  arises  for  there  being  some  system  of  co-ordination 
whereby  these  innumerable  stimuli  shall  be  suitably  responded 
to.  And  such  a  system  of  co-ordination  is  rendered  possible, 
and  actually  realized,  through  this  principle  of  reflex  action. 
For  the  animal  body  is  so  arranged  that  the  innumerable 
nerve-centres,  or  ganglia,  are  all  more  or  less  in  communica- 
tion one  with  another,  and  so  receive  messages  from  all  parts 
of  the  body,  to  which  they  respond  by  sending  appropriate 
messages  down  the  nerve-trunks  supplying  the  particular 
groups  of  muscles  which  under  the  given  circumstances  it  is 
desirable  to  throw  into  contraction.  In  other  words,  when  a 
stimulus  falls  upon  the  external  surface  of  an  animal,  it  is 
not  diffused  in  a  general  way  throughout  the  whole  body  of 
the  animal,  so  causing  general  and  aimless  contractions  of  all 
the  muscles ;  but  it  passes  at  once  to  a  nerve-centre,  and  is 
there  centralized;  the  stimulus  is  dealt  with  in  a  manner 
which  leads  to  an  appropriate  response  of  the  organism  to 
that  stimulus.  For  the  nerve-centres  which  receive  the 
stimulus  only  reflect  it  to  those  particular  nmscle-groups 
which  it  is  desirable  for  the  organism,  under  the  circumstances, 
to  throw  into  action.  Thus,  to  take  an  example,  when  a 
small  foreign  body,  such  as  a  crumb  of  bread,  lodges  in  the 
windpipe,  the  stimulus  which  it  there  cause?  is  immediately 
conveyed  to  a  nerve-centre  in  the  spinal  cord,  and  this  nerve- 
centre  then  originates,  by  reflex  action,  a  highly  complicated 
series  of  muscular  movements  which  we  call  coughing,  and 
which  clearly  have  for  their  very  special  object  the  expul- 
sion of  the  foreign  body  from  a  position  of  danger  to  the 
organism.  Now  it  is  obvious  that  so  complicated  a  series 
of  muscular  movements  could  not  be  performed  in  the 
absence  of  a  centralizing  mechanism ;  and  this  is  only  one 
instance  among  hundreds  of  others  that  might  be  adduced  of 

*  The  term,  however,  is  not  a  hnppv  one,  because  the  procesB  is  some- 
thing more  thiui  the  reliection  of  the  original  stimulus  or  moicuuliir  disturb- 
ance ;  the  ganglion  adds  a  new  disturbance. 


if 


28 


MENTAL  EVOLUTION  IN  ANIMALS. 


Of  course  we  may  wonder  how  it  is  that  the  nerve-centres 
which   preside  over  reflex  action,  not  being  endowed  wTth 
consciousi^ss,  know  wliat  to  do  with  the  stimuli  which  U^ey 
receive     The  explanation  of  this,  however,  is  that  the  ana^ 
tomical  arrangement  of  ganglion  and  nerves  in  any  particular 
case  IS  such  as  to  leave  no  choice  or  alternative  of  action  If 
the  apparatus  is  called  into  action  at  all.     Thus  to  benin'at 
he  bottom  of  the  series,  in  the  Medusa  the  simple  j^i^h a 
are  distributed   all  round   the   margin  of  the  animal,  ad 
respond  by  reflex  action  to  the  stimuli  which  are  applied  at 
any  other  part  of  the  surface.     This  has  the  effect  of  ^hicreas- 
mg  the  rate  and  the  str.^ngth  of  the  swimming-movements 
and  so  of  enabling  the  animal  to  escape  from  tlie  souZof 
diuiger.     Now,  although  this  is  a  true  reflex  action,  and  has 
an  obvious  purpose  to  serve,  it  does  not  involve  any  co-ordi 
nation  of  nuiscular  movements.     For  the  anatomical  plan  of 
a  jelly-fish  is  so  simple,  that  all  the  muscular  tissue  in  the 
body  IS  spread  out  m  the  form  of  one  continuous  sheet:  so 
tliat  the  only  function  which  the  marginal  ganglia  have  to 
peiform  when  they  are  stimulated  into^eflex  ac'tion,  iHhat 
tissur'""'"^  '"     contraction  one  continuous  sheet  of  muscular 

i.  ^fir  ^^  "'•'^y  i"^^^  ^^^^  in  its  earliest  stages  reflex  action 
IS  nothing  more  than  a  promiscuous  discharge  of  nervous 
energy  by  nerve-cells,  when  they  are  excited  by  a  stimidu. 
passing  into  them  from  their  attached  nerve-fibres  *  But  as 
animals  become  more  highly  organized,  and  distinct  muscles 
are  by  degrees  set  apart  for  the  performance  of  distinct  actions 
vve  can  readi  y  understand  how  particular  nerve-centres  are 

piirnf  I  "'""'  ''*  ^P^'^  ^°  P'^^i^*^  o^er  these  distinct 
actions;  the  nervous  centres  then  perform  the  part  of  tri-. 
gers  to  the  particular  muscular  mechanisms  over  which  the'V 

Hon 'nf  ";;^''°f ''i  ""^"fl'  .^^^'^  ""^y  ^^  ^^'^■'^ened  by  the  recep- 
tion  of  stimuli  along  their  own  particular  lines  of  communi- 
cation,  or  nerves.  Thus,  for  instance,  in  the  star- fish-animals 
tuVlT  somewhat  higher  in  the  zoological  scale  than  the 
jelly-fish,  and  which  have  a  more  highly  deA'eloped  neuro- 
muscular  system-the  ganglia  are  arranged  in  a  ring  round 

*  Fo';f'j^^"ll"ccountofrelIex.ictioninMeclu8,e,8eei'At7  Trans    Crooning. 
Lecture,  VSib;  also  mi.  Trans.,  1877  and  1880  '  ^'°°'"*** 


'ii 


THE  STRUCTURE  AND  FUNCTIONS  OF  NERVE -TISSUE.       29 

tho  bases  of  tho  fivo  rays,  into  which  they  send,  and  from 
whicli  they  receive,  nerve-fibres;  tho  ganj/lia  are  likewise 
connected  with  one  another  by  a  penta<^onal  ring  of  fibres. 
Now  experiment  shows  that  in  this  simple,  and  indeed  geo- 
metrical plan  of  a  nervous  system,  the  constituent  parts  are 
able,  when  isolated  by  section,  to  preside  over  tho  movements 
of  their  respective  muscles ;  for  if  a  singlo  ray  be  cut  off  at 
its  base,  it  will  behave  in  all  respects  just  like  tho  entire  star- 
fish— crawling  away  from  injury,  towards  light,  up  perpen- 
dicular surfaces,  and  righting  itself  when  turned  upon  its 
back.     That  is  to  say,  the  single  nerve-centre  at  the  base  of 
a  single  separated  ray  is  able  to  do  for  that  ray  what  the 
entire  pentagonal  ring,  or  central  nervous  system,  is  able  to 
do  for  the  entire  animal ;  it  is  for  that  ray  the  trigger  which, 
when  touched  by  the  advent  of  a  stimulus,  throws  the  mus- 
cular mechanism  into  appropriate  action.     Thus  it  is  evident 
that  each  of  the  five  nerve-centres  stands  in  such  anatomical 
relation  to  the  muscles  of  its  own  ray,  that  when  certain 
stimuli  fall  upon  the  ray,  the  process  of  reliex  action  leaves 
no  choice  of  response.     The   beauty  and  delicacy   of  this 
mechanism  is  shown  when  in  the  unmutilnted  animal  all  the 
nerve-centres  are  in  communication  as  one  compound  nerve- 
centre.     For  now,  if  one  ray  is  irritated,  all  the  rays  will 
co-operate  in  making  the  animal  crawl  away  from  the  source 
of  irritation;  if  two  opposite  rays  are  simultaneously  irri- 
tated, the  star-fish  will  crawl  away  in  a  direction  at  right 
angles  to  an  imaginary  line  joining  the  two  points  of  irrita- 
tion.   And,  more  prettily  still,  in  the  globular  Echinus,  or 
sea-urchin  (which   is,   anatomically  considered,  a  star-fish 
whose  five  rays  have  become  doubled  over  in  the  form  of  an 
orange,  soldered  together  and  calcareous  so  as  to  make   a 
rigid  box),  if  two  equal  stimuli  be  applied  simultaneously  at 
any  two  points  of  the  globe,  the  direction  of  escape  will  be 
the  diagonal  between  them ;  if  a  number  of  points  be  simul- 
taneously irritated,  one  effect  neutralizes  the  other,  and  the 
animal  rotates  upon  its  vertical  axis ;  if  a  continuous  zone  of 
injury  be  made  all  the  way  round  the  equator,  the  same  thing 
happens ;  but  if  the  zone  be  made  wider  at  one  hemisphere 
than  the  other,  the  animal  will  crawl  away  from  the  greatest 
amount  of  injurij.   So  that  in  the  Echinoderms  the  geometrical 
distribution  of  the  nervous  system  admits  of  our  making  ex- 
periments in  reflex  action  with  very    precise  quantitative 


m 


»' 


30 


MENTAL  EVOLUTION  IN  ANIMALS. 


«d'  .tn  n !  T?  •  ""'  ''  ""''''  P^'^^y  "P°"  t'^i^  beautifully 
adjusted  mechanism,  so  as  to  produce  at  will  the  balancincr  or 
this  stimulus  against  that  one-the  results,  as  expressed  in 

forces  *  "mechanical  principle  of  the  parallelogram  of 

As  we  proceed  through  th.  animal  series  we  find  nervous 
systems  becoming  more  and  more  integrated ;  nerve-centres 
multiply,  become  larger,  and  serve  to  innervate  more  numerous 
and  more  complex  groups  of  muscles.     It  is,  however,  need- 
less for  me  to  devote  space  to  describing  this  advance  of 
structure,  because  the  subject  is  one  belonging  to  compara- 
tive  anatomy.     It  is  enough  to   say  that  everywhere  the 
nervous  machinery  is  so  arranged  that,  owing  to  the  ana- 
tomical plan  of  a  nerve-centre  with  its  attached  nerves  there 
18  no  alternative  of  action  presented  to  the  nerve-centre 
other  than  that  of  co-ordinating  the  group  of  muscles  over 
the  combined  contraction  of  which  it  presides      The  next 
question  therefore,  which  arises  is-How  are  we  to  explain 
the   fact  that  the   anatomical  plan  of  a  ganglion,  with  its 
attached  nerves,  comes  to  be  that  which  is  needed  to  direct 
the  nervous  tremours  into  the  particular  channels  required  ? 
Tlie  following  is  the  theory  whereby  Mr.  Herbert  Spencer 
seeks  to  answer  this  question,  and  in  order  fully  to  under- 
stand It  we  must  begin  by  noticing  the  effects  of  stimulation 
upon  undifferentiated  protoplasm.     A  stimulus,  then,  api^Iied 
to  homogeneous  protoplasm,  which  is  everywhere  contractile 
and  nowhere  presents  nerves,  hos  the  effect  of  mvin.T  rise  to 
a  visible  wave  of  contraction,  which  spreads  in  all  cUrections 
from  the  seat  of  stimulation  as  from  a  centre.    A  nerve  on 
the  other  hand,  conducts  a  stimulus  without  undergoincr  any 
contmction,   or  change  of  shape.     Nerves,  then,  are°func- 
t  oually  distinguished  from  undifferentiated   protoplasm   bv 
the  property  of  conducting  invisible  or  molecular  waves  of 
fitimula  ion   from  one   part  of  an   organism  to  another,  so 
establishing    physiological    continuity  between  such    parts 
vvitliout  the  necessary  passage  of  visible  waves  of  contraction 
:Now  beginning  with  the  case  of  undifferentiated  proto- 
plasm, Mr  Spencer  starts  from  the  fact  that  every  portion  of 
the  colloidal  mass  is  equally  excitable  and  equally  contrac- 

Translmt^^  ^''''""'  ""^  '''"'  experiiDeuts,  see  Croonian  Leclure,  I>UU. 


THE  STRUCTURE  AND  FUNCTIONS   OF  NERVE-TISSUE. 


31 


tile.  But  soon  after  protoplasm  begins  to  assume  definite 
shapes,  recognized  by  us  as  specific  forms  of  life,  some  of  its 
parts  are  habitually  exposed  to  the  action  of  forces  different 
from  those  to  which  other  of  its  parts  are  exposed.  Conse- 
quently, as  protoplasm  continues  to  assume  more  and  more 
varied  forms,  in  some  cases  it  must  happen  that  parts  thus 
peculiarly  situated  with  reference  to  external  forces  will  be 
more  frequently  stimulated  to  contract  than  are  otlier  parts 
of  the  mass.  Now  in  such  cases  the  relative  frequency  with 
which  waves  of  stimulation  radiate  from  the  more  exposed 
parts,  will  probably  liave  the  effect  of  creating  a  sort  of  polar 
arrangement  of  the  protoplasmic  molecules  lying  in  the  line 
through  which  these  waves  pass,  and  for  other  reasons  also 
will  tend  ever  more  and  more  to  convert  these  lines  into 
passages  offering  less  and  less  resistance  to  the  flow  of  such 
molecular  waves, — i.e.,  waves  of  stimulation  as  distinguished 
from  waves  of  contraction.  And  lastly,  when  lines  offering 
a  comparatively  low  resistance  to  the  passage  of  molecular 
impulses  have  thus  been  organically  established,  they  must 
then  continue  to  grow  more  and  more  definite  by  constant 
use,  until  eventually  they  become  the  habitual  channels  of 
communication  between  the  parts  of  the  contractile  mass 
through  which  they  pass.  Thus,  for  instance,  if  such  a  line 
has  been  established  l)etween  the  points  A  and  B  of  a  con- 
tractile mass  of  protoplasm,  when  a  stimulus  falls  upon  A,  a 
molecular  wave  of  stimulation  will  course  through  that  line 
to  B,  so  causing  the  tissue  at  B  to  contract — and  this  even 
though  no  wave  of  contractio,i  has  passed  through  the  tissue 
from  A  to  B.  Such  is  a  very  meagre  epitome  of  Mr.  Spencer's 
theory,  the  most  vivid  conception  of  which  may  perhaps  be 
conveyed  in  a  few  words  by  employing  his  own  illustration, 
viz.,  that  just  as  water  continually  widens  and  deepens  the 
(-■  irxuel  through  which  it  flows,  so  molecular  waves  of  the 
k.uid  we  are  considering,  by  always  flowing  in  the  same 
tissue  tracts,  tend  ever  more  and  more  to  excavate  for  tliem- 
selves  functionally  differentiated  lines  of  passage.  When 
such  a  line  of  passage  becomes  fully  developed,  it  is  a  nerve- 
fibre,  distinguishable  as  such  by  the  histologist ;  but  before  it 
arrives  at  this  its  completed  stage,  i.e.,  before  it  is  observable 
as  a  distinct  structure,  Mr.  Spencer  calls  it  a  "  line  of  dis- 
charge."* 

*  A  certain  amount  of  experimental  verification  lias  been  lent  to  this 


32 


MENTAL  EVOLUTION  IN  ANIMALS. 


arise  in  positions  wWo'o-       ™PP°'"=s  nerve-cells,  to 

tion^?rrtv;^-nn""v^?^^^^ 

plan  of  a  ffan^lion  wifli  ifi  Xni   i  *"®  anatomical 

tion  that  "  practice  makes  ,,ZZ?'^f^  ?,'-'^'"^l°^''""^ 
that  the  co-ordinations  of  Sf,  !.  .'  ^  ""'  ""'^  ""=*»« 
presided  over  hv  tl?=      <>'  "  "s"'Iar  movement  which  are 

^e^dy  terZ.^a'r     e  l^X^^XTy  t''"Y  """' 

moi^rLdS'ty'Lf.h%h"    fenXr'""  T^'  '","^  ""^ 
uit  case,  that  when  an  associated  muscular 

i?o.va^/«*^Y«^-o«tWl877  on  "SnfP  fi^'^  '"  '^  Proceedings  of  the 
are  that  when  physiological  contiSt  of  a  «f  ."T '  ^^^  P"""P"1  ^"^^^ 
interrupted  by  overj.pjing  or;S^«.  f        ^^    of  neuro-niuscular  tissue  is 

visible  or  n.us-'cularJ^r^f^'onCt  on  InTin:-M''  ""^  ^^^"^6  both  of 
stimulation  are  blocked,  after  a  lon°  „""?  ^''•".^  or  molecular  wares  of 
allowed  to  break  upon  the  8hLorfLr'''r-°'^^'""'''«''^^°"  ^^^^s  are 
last  begin  to  force  a^passagerd  very  sol^S"""^  i^^terruption,  they  at 
free,  so  that  neither  the  waves  of  Jr, ft  f  ^"'^"^0  becomes  perfectly 

any  longer  hindered.  Whether  in  such  I  °''  "^''.^i"^"  ""^  stin.uhVtion  are 
veloped.  or  only  a  "line  o  ItlL"  1  ean.^ot  «"  ^^1"^  "^rve-flbre  is  de- 
passage  is  effected  through  prcvi^usW  exS  fl^ '  but  most  probably  the 
become  more  functionally  develoDerrhv  fV.i    -^  ^^'''  ?^  "'^  P^^^"«  ^^'i^li 

•  Less  Batisfactory  not  ,In  v^hl/  '''"''''^  °^  "^^"^i^^- 

whole  weight  of  emSydogica"  Ld  w!^^  speculative,  bilt  because  the 

opposed  to  the  speculation^  iC  the  S°fi'  '',"  '"f  ^PP^"^''^  *°  '"^  *«  be 
show  that  nerve-cells  are  ?ho  resul  of  llf  "f  "  ^*  *'"^  ''^■'^'^'•''''  ^^^  ^o 
dermal  cells-that  is  thntfLT    •  l^  specialization  of  epithelial  or  epi- 

but  by  way  of  a  f uXr  d  feraUon  oT'  °'  "-'''^-^"^^'^'''^  protoplas?;;. 
ferentiated  tiaaue,  where  ^^^^^S^S^^^^^^  t^^^' 


m 


THE  STRUCTUEE  AND  FUNCTIONS  OF  NERVE-TISSUE.       33 

movement  takes  place  with  sufficient  frequency,  it  cannot  by 
any  effort  of  the  will  become  again  dissociated ;  as  is  the  case, 
for  instance,  with  the  associated  movement  of  the  eyeballs, 
which  does  not  begin  to  obtain  till  some  days  after  birth,  but 
whicli  then  soon  becomes  as  closely  organized  as  any  of  the 
associated  movements  in  the  muscles  of  the  limbs  * 

And  if  this  is  the  case  even  in  the  life-time  of  individuals, 
we  can  scarcely  wonder  that  in  the  life-time  of  species  heredity 
with  natural  selection  should  still  more  completely  adapt  the 
anatomical  plan  of  ganglia,  with  their  attached  nerves,  to  the 
performance  of  the  most  useful — i.e.,  the  most  habitual — 
actions.  Thus  we  may  see  in  a  general  way  how  such  nei'vous 
machiner}"  may  at  last  come  to  be  differentiated  into  specially 
distributed  anatomical  structures,  which,  on  account  of  their 
special  distribution,  are  adapted  to  minister  only  to  particular 
co-ordinations  of  muscular  movements.  That  is  to  say,  we 
are  thus  able  to  understand  the  rise  and  development  of 
Keflex  Action. 


of 


*  Mr.  Darwin  called  my  attention  to  the  following  passage  in  the  writings 
Lamarck  (FAil.  Zool.,  torn,  ii,  pp.  318-19)  : — "  Dans  toute  action,  lo 
fluide  des  nerfs  qui  la  provo(|ue,  subit  un  mouveraent  de  deplacement  qui  y 
donne  lieu.  Or,  lorsque  cette  action  a  ete  plusieurs  fois  repetee,  il  n'est  pas 
douteux  que  le  fluide  qui  I'a  executee,  ne  se  soit  fraye  une  route,  qui  lui 
devient  alors  d'autant  plus  facile  h  parcourir,  qu'il  I'a  eiJ'ectivement  plus 
souvant  francliie,  et  qu'il  n'ait  lui-meme  une  aptitude  plus  grand  i  auivre 
cette  route  frayee  que  celles  qui  le  sout  moina." 


'*?fe 


I  i 


34 


MENTAL  EVOLUTION  IN  ANIMAL* 


CHAPTER  III. 


The  Physical  Basis  of  Mind. 


1;   f 


< 


Vi 


We  have  already  taken  it  for  granted  that  Mind  has  a 
physical  basis  m  the  functions  of  the  nervous  system  or  that 
every  mental  process  has  a  corresponding  equivalent  in  some 
neural  process.  I  shall  next  endeavour  to  show  how  precise 
tnis  equivalency  is. 

We  have  seen  that  ganglionic  action  consists  of  waves  of 
nervous  tremours  originating  in  the  cells,  coursing  along  the 
attached  hbi-es  to  other  cells,  and  there  arousing  fresh  impulses 
ot  the  same  kind.    Moreover,  we  have  seen  that  this  coursincr 
ot  nervous  impulses  through  nervous  arcs  is  not,  as  it  were° 
promiscuous,  but  that,  owing  to  the  anatomical  plan  of  a 
ganglion,  it  takes  place  in  certain  determinate  directions,  so 
that  the  result  when  expressed  in  muscular  movement,  shows 
the  function  of  a  ganglion  to  be  that  of  centralizing  nervous 
action,  or  of  directing  nervous  tremours  into  definite  channels 
Last  y,   we   have   seen  that  this   directing  or  centralizinor' 
function  of  ganglia  has  probably  in  all  cases  been  due  to  thS 
principle  of  use  combined  with   that  of  natural  selection 
JVow  It  18  known  from  experiments  on  the  lower  animals,  as 
well  as  from  the  effects  of  cerebral  disease  in  man,  that  the 
part  of  the  nervous  system  in  all  the  Vertebrata  which 
appears  to  be  exclusively  concerned  in  all  mental  operations 
is  the  so-called  "  large  brain,"  or  cerebral  hemispheres     This 
IS  the  convoluted  part  of  the   brain  which  appears  imme- 
diately below  the  skull,  and  is  above  all  the  series  of  cran'dia 
or  nerve-centres  which  occupy  the  rest  of  the  cerebro-spfnal 
tract     As  some  at  least  of  the  bewildering  multitude  of  cells 
and  fibres  which  constitute  the  cerebral  hemispheres  are  in 
connection  with  these  lower  ganglia,  there  is  no  doubt  that 
the  hemispheres  are  able  to  "play  down"  upon  these  gano-lia 
as  upon  so  many  mechanisms,  whose  function  it  is  to  throw 


f '  I 


THE  niYSICAL  BASIS  OF  MIND. 


35 


this  and  that  group  of  muscles  into  action.  Much  light  is  at 
present  being  thrown  upon  this  subject  by  the  researclies  of 
Hitzig,  Fritsch,  Ferrier,  Goltz,  and  others ;  but  we  must  pass 
on  to  consider  that  function  of  these  great  nerve-centres  with 
which  we  shall  henceforth  be  exclusively  concerned,  the 
function,  namely,  of  being  associated  with  the  phenomena  of 
Mind. 

As  the  cerebral  hemispheres  pretty  closely  resemble  in 
their  intimate  structure  ganglia  in  general,  there  can  be  no 
reasonable  doubt  that  the  mode  of  their  operation  is  substan- 
tially the  same ;  and  as  such  operation  is  here  attended  with 
the  phenomena  of  subjectivity,  there  can  be  equally  little 
doubt  that  such  phenomena  must  constitute  a  sort  of  obverse 
reflection  of  ganglionic  action.  Looking,  then,  upon  this 
obverse  reflection,  can  we  detect  any  fundamental  principles 
of  mental  operation  which  may  reasonably  be  taken  to  corre- 
spond with  the  fundamental  principles  of  ganglionic  opera- 
tion? 

The  most  fundamental  principle  of  mental  operation  is 
that  of  memory,  for  this  is  the  conditio  sine  qud  non  of  all 
mental  life.  But  memory  on  its  obverse  side,  or  the  side  of 
physiology,  can  only  mean  that  a  nervous  discharge,  having 
once  taken  place  along  a  certain  route,  leaves  behind  it  a 
molecular  change,  more  or  less  permanent,  such  that  when 
another  discharge  afterwards  proceeds  along  the  same  route, 
it  finds,  as  it  were,  the  footprints  of  its  predecessor.  And 
this,  as  we  have  seen,  is  no  more  than  we  find  to  be  the  case 
with  ganglionic  action  in  general.  Even  long  before  move- 
ments involving  muscular  co-ordination  have  been  repeated 
with  sufficient  frequency  to  become  consolidated  into  one 
organized  and  indissoluble  act,  they  become,  in  virtue  of  the 
principle  which  I  have  termed  the  principle  of  use,  more  and 
more  easy  to  repeat ;  in  all  but  in  the  absence  of  a  mental 
constituent  the  nerve-centre  concerned  remenibcrs  the  pre- 
vious occurrence  of  its  OAvn  discharges ;  these  discharges  have 
left  behind  them  an  impress  upon  the  structure  of  the 
ganglion  just  the  same  in  kind  as  that  which,  when  it  lias 
taken  place  in  the  structure  of  the  cerebral  hemispheres,  we 
recognize  on  its  obverse  side  as  an  impress  of  memory.  The 
analogy  is  much  too  close  to  be  attributed  to  accident,  for  it 
extends  into  all  details.  Thus,  a  ganglion  may  funjet  it3 
previous  activity  if  too  long  an  interval  is  allowed  to  elapse 


36 


MENTAL  EVOLUTION  IN  ANIMALS. 


between  tlie  repetitions  of  its  activity,  as  every  one  must 
know  who  is  in  the  habit  of  playing  on  a  musical  instrument, 
or  performing  any  other  actions  entailing  the  acquirement  of 
dexterity.  It  may  also  be  observed  that  when  such  is  the 
case  the  particular  activity  forgotten  by  the  ganglion  may  be 
more  easily  re-acquired  than  oridnolly  it  was  acquired,  which 
is  just  what  we  find  to  be  tht  'vfch  mental  attainments. 

As  particular  illustrations  ■'  '■.  ,e  facts  I  may  state  two 
or  three  cases,  which  will  also  ■  ..ve  to  show  of  how  little 
importance  (on  the  objective  side)  is  the  occurrence  of  con- 
sciousness to  the  memory  of  a  ganglion. 

Eobert  Houdin  early  in  life  practised  the  art  of  juggling 
with  balls  in  the  air,  and  after  a  month's  practice  was  able  to 
keep  four  balls  in  the  air  at  once.  His  neuro-muscular 
machinery  was  now  so  well  trained,  or  remembered  so  well 
how  to  perform  the  series  of  actions  required,  that  he  could 
attbrd  to  withdraw  his  attention  from  the  performance  to  the 
extent  of  reading  a  book  without  hesitation  while  keeping 
up  the  four  balls.  Thirty  years  afterwards,  on  trying  the 
same  experiment,  having  scarcely  once  handled  the  balls 
between  times,  he  found  that  he  could  still  read  with  ease 
while  keeping  up  three  balls ;  the  ganglia  concerned  had 
partly  forgotten  their  work,  but  on  the  whole  remembered  it 
wonderfully  well.  Again,  Lewes  gives  the  case  of  a  waiter 
asleep  at  a  coffee-house,  with  much  noise  of  talking  arouncl 
him,  who  was  instantly  aroused  by  a  low  cry  of  "  Waiter ;" 
and  Dr.  Abercrombie  gives  the  case  of  a  man  who  had  long 
been  in  the  habit  of  taking  down  a  repeater  watch  from  the 
head  of  his  bed  to  make  it  strike  the  last  hour,  and  who 
was  observed  to  do  this  when  otherwise  apparently  uncon- 
scious from  a  fit  of  apoplexy.  But  perliaps  the  most  remark- 
able of  all  the  cases  that  can  be  adduced  are  the  most  familiar 
ones  of  walking  and  speaking.  When  we  remember  the 
immense  amount  of  neuro-muscular  co-ordination  that  is 
required  for  either  of  these  actions,  and  the  laborious  steps 
by  which  each  of  them  is  first  acquired  in  early  childhood,  it 
is  indeed  astonishing  that  in  after  life  they  come  to  be  per- 
formed without  thought  of  their  performance ;  the  ganglia 
concerned  have  fully  learned  their  work. 

So  much  for  memory.  But  memory  would  be  a  useless 
faculty  of  mind  if  it  did  not  lay  the  basis  for  another,  and 
really  the  most  important  principle  of  subjectivity ;  I  mean 


/ 


u 


THE  PHYSICAL   BASIS   OF  MIND. 


87 


the  Association  of  Ideas.  This  is  the  root  and  branch  of  the 
whole  structure  psychological,  and  therefore,  if  mind  has  a 
physical  basis,  we  should  expect  to  meet  with  some  very 
aeneral  and  essential  feature  of  ganglionic  action  answering 
to  tliis  very  general  and  essential  feature  of  mental  action. 
And  this,  beyond  question,  we  do  find. 

For  the  association  of  ideas  is  merely  a  development  of 
simple  memory.  A  mental  impression,  image,  memory,  or 
idea  having  once  occurred  in  juxtaposition  with  another,  not 
only  are  the  two  memories  remembered,  but  also  the  fact  of 
their  juxtaposition,  so  that  when  one  memory  or  idea  is 
aroused,  the  other  is  aroused  likewise.  Let  us,  then,  look  at 
the  matter  a  little  more  closely,  in  order  to  see  how  this  great 
principle  of  psychology  may  receive  its  explanation,  so  far  as 
the  collateral  principle  of  physiology  is  concerned. 

There  can  be  no  doubt  that  in  the  complex  structure  of 
the  cerebral  hemispheres  one  nervous  arc  (i.e.,  fibres,  cells, 
and  fibres)  is  connected  with  another  nervous  arc,  and  this 
with  another  almost  ad  infinitum ;  and  there  can  be  equally 
little  doubt  that  processes  of  thought  are  accompanied  by 
nervous  discharges  taking  place,  now  in  this  arc,  and  now  in 
that  one,  according  as  the  group  of  nerve-cells  in  each  arc  is 
excited  to  discharge  its  influence  by  receiving  a  discharge 
from  some  of  the  other  nerve-arcs  with  which  it  is  united. 
Again,  as  we  have  seen,  it  is  practically  certain  that  the 
more  frequently  a  nervous  discharge  takes  place  through  a 
given  group  of  nervous  arcs,  the  more  easy  will  it  be  for  sub- 
sequent discharges  to  take  place  along  the  same  routes— these 
routes  having  been  thus  rendered  more  permeable  to  the  pas- 
sage of  subsequent  discharges.     And  now  a  very  little  reflec- 
tion will  show  that  in  this  physiological  principle  we  no 
doubt  have  the  objective  side  of  the  psychological  principle 
of  the  association  of  ideas.    For  it  may  be  granted  that  a 
series  of  discharges  taking  place  through  the  same  group  of 
nervous  arcs  will  always  be  attended  with  the  occurrence  of 
the  same  series  of  ideas  ;  and  it  may  be  further  granted  that 
the  previous  passage  of  a  series  of  discharges  through  any 
group  of  nervous  arcs,  by  making  the  route  more  permeable, 
will  have  the  effect  of  making  subsequent  discharges  pursue 
the  same  course  when  started  from  the  same  origin.     And  if 
these  two  propositions  be  granted,  it  follows  that  the  tendency 
of  ideas  to  rtcur  in  the  same  order  as  that  in  which  they 


'1^ ; 


S8 


MENTAL  EVOLUTION  IN  ANIMALS. 


i 


seen,;  o" r;-:^  t^^^ .^  tC  t^  Sf  initate^.^ 

Mu  injily  aue  to  a  conscious  association  of  ideas  mnv   liv  <, 
euthciently  long  course  of  ganglionic  instrucUon   cS  to^be 
conscious  actions,  and  therefore  become  m  no  way  distin 
guishable  from  reflex  actions.*  ^     ™°' 

IJut  the  proof  of  the  fundamental  correlation  between 

f  ?  TiLr"""  ?."  "i^^"""  ="=«»  does  not  end  Ive" 
here.  There  is  another  line  of  evidence  which  althom,?, 
perhaps  not  quite  so  dehnite,  nevertheless  seen  s  to  me  nS 

direaciy  adduced.     If  we  take  ideation  to  be  in  tliP  si  ma 
sense  an  index  of  the  higher  or  more  complex  «s  Z 
cesses,  as  muscular  movement  is  of  the  lower  or  less  comHpv 
we  shall  find  evidence  to  show  that  the  developri  t  of 

ueveiopment  ot  the  correspondmg  nervous  processes  wh,Vh 

plCZ'fof  ''"^.  '"  "^"^  ^^^^^^  whU  on  he  lower 
plane  (that  of  muscular  movement)  has  led  to  the  advanoini 

development  of  muscular  co-ordination.  In  otW  wo?ds  f 
we  consent  to  change  the  index  from  muscles  to  ideat;.^ 
shall  find  evidence  that  the  method  of  nervous  evolution  has 
P  X^  r ''^  been  uniform  ;  we  shall  find  that  the ToCssi^e 
elaboration  of  nervous  structures-which  in  the  one  SiS  Z 

X"Td  r  Jh  '"tr"^"-^  'T^^^^^  ''  ^mZZ 
system   and  m  the  other  case  has  been  reflected  in  fha 

advancing  phases  of  mental  evolution-we  shall  find  thl^  th^! 

progressive  elaboration  has  throughout  been  perv^^^ 

same  principles  of  development.  pervaaea  Dy  the 

while  women  Always  spiTadtheirW  *t  "'^  objeotsuch  as  a  coin! 

the  difference  of  dress  has  IpH  frT n  rfff    ^  /^''®  ''^'''°"  °^  ''°"^*''  i^  thab 

ia  each  case  having becrorinanrfr'tr"'  f  ^-^g^'^^f  habit-the  habit 
Bt-arcelj  distinguishable  from  a  ^^^    ^  '"''"'^""  "^J"«'"»^'°t.  but  now 


ijt       ; 


AX. 


THE  PHYSICAL  BASIS   OF  MIND. 


39 


Disregarding  the  philosophical  question  as  to  how  nervous 
action  IS  associated  with  subjective  ideation,  and  conceiniiicr 
ourselves  only  with  the  scientific  fact  that  it  is  thus  associatetf 
we  may  most  clearly  appreciate  the  parallel  whicli  I  am  about 
to  draw  if  we  regard  tbe  objective  processes  as  the  causes  of 
the  subjective.     Whether  or  not  such  is  really  the   case 
matters  nothing  to  the  exposition  on  which  I  am  about  to 
enter;  for  I  throughout  take  it  for  granted  that  the  association 
of  neurosis  and  psychosis  is  as  invariable  and  precise  as  it 
would  be  were  it  proved  to  be  due  to  a  relation  of  causality 
Placing  therefore  neurosis  for  the  purposes  of  my  arrrumerit 
as  the  cause  of  psycliosis,  I  desire  to  show  that  th  °re  is  a 
very  exact  parallel  between  the  ganglionic  action  which  pro- 
duces subjective  ideation  and  that  which  produces  muscular 
co-ordination;  I   desire  to  show  that  if   we   interpret  the 
phenomena  of  ideation  in  terms  of  the  nervous  activity 
which  IS  supposed  to  produce   it,  we  shall  find  that  tliis 
activity  IS  just  the  same  in  all  its  laws  and  principles  as  that 
winch  produces  muscular  co-ordination. 

_  No  doubt  it  sounds  absurd,   and  from  a  philosophical 
point  of  view  alone  it  is  absurd,  to  speak  of  ideas  as  the 
psychological  equivalents  of  muscles.     So  far  as  subjective 
analysis  could  teach  us,  it  certainly  does  not  seem  that  an 
idea  presents  any  further  kinship  to  a  muscle  than  it  does  to 
a  stoue,  or  to  the  moon ;  but  when  we  look  at  the  matter 
from  the  objective  side,  we  perceive  tliat  the  kinship  is  most 
intimate.     Taking  it  for  granted  that  the  same  idea  is  only 
and  always  aroused  during  the  activity  of  the  same  nervous 
structure,  element,  or  group  of  cells  and  fibres,  it  follows  that 
any  particular  mental  change  resembles  any  particular  mus- 
cular contraction  in  so  far  as  it  is  the  terminal  result  of  the 
activity  of  a  particular  nervous  structure.     The  inconoruity 
of  comparing  a  mental  change  to  a  muscular  contraction 
arises,  ot  course,  from  the  emphatic  distinction  which  must 
always  be  felt  to  exist  between  mental  and  dynamical  pro- 
cesses.   Physiology,  which  is  concerned  only  with  the  dyna- 
mical processes,  can  take  no  cognizance  of  anything  that 
happens  in  the  region  of  mind.     It  can  trace  nervous  action 
leading  to  combined  muscular  movements  of  greater  and 
greater  nitricacy  as  we  ascend  to  more  and  more  elaborated 
mechanisms;  but  even  when  we  reach  the  brain  of  man 
physiology  can  have  nothing  to  do  with  the  mental  side  of 


40 


MENTAL  EVOLUTION  IN  ANIJIALS. 


■|i 


'      H! 


the  nervous  processes.  All  that  physiology  can  see  in  these 
processes  is  a  greatly  improved  power  of  disrriniinating 
between  stimuli,  and  of  issuing  impulses  to  a  correspondingly 
greater  numl)er  and  variety  of  adaptive  movements  ;  the 
mental  changes  which  accompany  these  nervous  processes  are 
as  wliolly  without  the  ken  of  physiology  as  these  nervoua 
processes  are  without  the  ken  of  subjectivity.  Therefore  it 
is  that  when  we  speak  of  an  idea  as  the  analogue  of  a  muscle, 
we  feel  the  incongruity  of  confusing  two  things  which  are 
separated  from  one  another  by  the  whole  interval  that 
divides  subject  from  object.  But  although  in  speaking  of  an 
idea  as  the  analogue  of  a  muscle,  we  do  and  ought  to  feel  the 
incongruity,  let  it  not  be  supposed  that  by  thus  speaking  we 
are  allowing  ourselves  to  be  betrayed  into  any  confusion  of 
thought.  I  speak  of  a  mental  change  as  the  analogue  of  a 
muscular  contraction  only  with  reference  to  its  being  the  ter- 
minal event  invariably  associated  (whether  by  way  of 
causality  or  not)  with  the  activity  of  a  nervous  structure. 
And  if  we  do  not  seek  to  press  the  analogy  further  than  this, 
there  is  no  fear  of  our  confusing  ideas  which  ought  always  to 
be  kept  fundamentally  distinct. 

So  much,  then,  by  way  of  introduction  to  the  point  which 
I  have  to  make  plain.  Now  it  admits  of  being  abundantly 
proved  that  throughout  the  animal  kingdom,  so  long  as  we 
regard  the  muscular  system  as  our  index  of  the  structural 
advances  taking  place  in  the  nervous  system,  we  find  this 
index  to  consist  in  the  growing  complexity  of  the  muscular 
system,  and  the  consequent  increase  in  the  number  and 
variety  of  co-ordinated  movements  which  this  system  is 
enabled  to  execute.  Therefore  the  point  which  I  have  to 
prove  will  be  proved  if  I  can  make  it  clear  that  the  process 
of  mental  evolution  bears  some  such  resemblance  to  that  of 
niuscular  evolution  as  we  should  expect  that  it  ought  to  bear, 
if  they  are  both  dependent  on  a  similar  process  of  nervous 
evolution.  In  other  words,  I  have  to  show  that  the  process 
of  mental  evolution  consists  essentially  in  a  progressive 
co-ordination  of  progressively  developing  mental  faculties, 
analogous  to  that  which  takes  place  in  muscular  movements. 

Beginning  with  the  faculties  of  simple  sensation,  we 
know,  for  instance,  that  when  a  note  of  music  is  struck,  it 
appears  to  produce  a  single  vibration,  and  yet  physical  ana- 
lysis shows  that  the  sound  is  not  a  single  vibration,  but  a 


i  ' 


THE  PHYSICAL  BASIS  OF  MIND. 


41 


liijilily  complex  structure  of  vibrations  or  harmonics,  and  that 
the  ear  takes  in  all  tliese  harmonics  by  as  many  separate 
nervous  elements  (whatever  the  elements  may  be  which 
minister  to  the  perception  of  pitch),  although  they  are  all 
blended  into  one  compound  sensation,  which  is  so  well  com- 
pounded that  the  evidence  supplied  by  it  alone  would  never 
have  led  us  to  suspect  that  the  sensation  was  other  than 
simple.  The  same  is  known  to  be  the  case  with  sensations 
of  colour,  taste,  and  smell ;  so  that  Lewes  feels  justified  in 
going  to  the  length  of  saying,  "  Every  sensation  is  a  group  of 
eensible  components."*  And,  taking  the  same  view  on  the 
psychological  side  as  I  take,  he  further  says  in  general  terms, 
"  The  main  fact  on  which  our  exposition  rests  is  indisputable, 
namely,  that  sensation,  perception,  emotions,  conceptions,  are 
not  simple  undecomposable  states,  but  variously  com- 
pounded." 

To  avoid  being  tedious,  I  shall  not  pursue  the  analysis 
through  all  the  grades  of  the  psychological  faculties ;  but, 
taking  ideation  in  its  widest  sense,  as  including  alike  the 
mere  memory  of  a  sensation  and  the  most  complex  process 
of  abstract  thought,  I  shall  briefly  show  that  it  everywhere 
displays  a  grouping  and  compounding  of  subjective  elements 
which,  if  translated  into  their  objective  counterparts,  display 
precisely  the  same  method  of  nervous  evolution  as  that  which 
obtains  in  the  lower  ganglia,  as  expressed  by  muscular  co- 
ordination. 

As  Bain  observes,  "Movements  frequently  conjoined 
become  associated,  or  grouped,  so  as  to  arise  in  the  aggregate 
at  one  bidding.  Suppose  the  power  of  walking  attained,  and 
also  the  power  of  rotating  the  limbs,  one  may  then  be 
taught  to  combine  the  walking  pace  with  the  turning  of  the 
toes  outward.  Two  volitions  are  at  first  requisite  for  this  act, 
but  after  a  time  the  rotation  of  the  limb  is  combined  with 
the  act  of  walking,  and,  unless  we  wish  to  dissociate  the  two, 
they  go  together  as  a  matter  of  course ;  the  one  resolution  brings 

on  tlie  combined  movement Articulate  speech 

largely  exemplifies  the  aggregation  of  muscular  movements 
and  positions.  A  concurrence  of  the  ch.est,  larynx,  tongue, 
and  mouth,  in  a  definite  group  of  exertions,  is  requisite  for 
each  alphabetical  letter.    These  groupings,  at  first  impossible, 


Problems,  ^c,  p.  260. 


42 


MENTAL  EVOLUTION  IN  ANIMALS. 


l! 


are,  after  a  time,  cemouted  with  aU  the  firmness  of  the 
strongest  instinct." 

Precisely  analogous  to  this  process  of  Uendiri'^  many 
Beparato  muscuhjr  ir.ovements  into  one  simultaneous  and  com- 
pounded movement,  is  the  process  of  blending  many  simiile 
Kl-is  into  one  complex  or  compounded  idea.  Just  as  mus- 
cular  co-ordination  is  dependent  on  the  simultaneous  action 
ot  a  certain  group  of  nerve-centres  for  the  purpose  of  securinr» 
tlio  combined  action  of  a  number  of  muscles,  so  wo  must 
suppose  that  a  general  or  a  composite  idea  is  dependent  on 
the  simultaneous  activity  of  several  nerve-centres  which 
I  muster  to  the  several  component  parts  of  the  blended  idea, 
llie  psychological  side  of  this  process  has  been  so  well  ex- 
pressed by  James  Mill,  that  I  cannot  do  better  than  render  it 
in  his  words :— "  Ideas  which  have  been  so  often  conioined 
tliat  whenever  one  exists  in  the  mind  the  other  exists  alon-r 
with  It,  seem  to  run  into  one  another,  to  coalesce,  as  it  wercT 
and  out  of  many  to  form  one  idea,  wliich  idea,  however  in 
reality  complex,  appears  to  be  no  less  simple  than  any  one  of 

tliose  of  which  it  is  compounded The  word 

•  gold,'  for  example,  or  the  word  '  iron,'  appears  to  express  as 
simple  an  idea  as  the  word  '  colour,'  or  the  word  '  sound ' 
let  it  18  immediately  seen  that  the  idea  of  each  of  those 
metals  13  made  up  of  the  separate  ideas  of  several  sensa- 
tions :  colour,  hardness,  extension,  weight.     TJiose  ideas,  how- 
ever, present  themselves  in  such  intimate  union,  that  they 
are  constantly  spoken  of  as  one,  not  many.     We  say,  our 
Idea  of  iron,  our  idea  of  gold;  and  it  is  only  with  an  effort 
that  reflecting  men  perform  the  decomposition."     And  simi- 
larly, of  course,  with  the  most  highly  complex  ideas,  except 
that  the  more  complex  they  becon)«.  the  greater  is  the  diffi- 
culty of  securing  the  needful  composition,  and  the  more  easily 
do  they  undergo  disintegration.     Thus  it  is  that,  in  the  words 
ot  Mr.  Spencer,  "  In  the  development  of  mind  there  iij  a  pro- 
gressive consohdation  of  states  of  consciousness.     States  of 
consciousness  once  separate  become  indissoluble.    Other  states 
that  were  originaUy  united  with  difficulty,  grow  so  coherent 
as  to  follow  one  another  without  difficulty.     And  thus  there 
arise  large  aggregations  of  states,   answering    to    complex 
external  things— animals,    men,    buildings— which   are    so 
welded  together  as  to  be  practically  single  states.     But  this 
integration,  by  uniting  a  large  number  of  related  sensations 


%     :,. 


1*1 


THE  PHYSICAL  BASIS  OP  MIND. 


43 


into  one  state,  does  not  destroy  them.    Though  subordinated 
as  parts  of  ii  whole,  they  still  exist."* 

Again,  just  as  the  principle  of  association  is  exhibited  in 
the  case  of  ideas  not  only  with  reference  to  the  simaltanams 
blending  of  siniplu  ideas  into  one  complex  idea,  but  also 
with  reference  to  the  succcssirc  sequence  or  concatenation  of 
ideas ;  so  in  the  case  of  muscular  co-ordinations  we  acipiire, 
not  only  the  power  of  a  simultaneous  co-operation  of  muscle- 
groups,  but  also  that  of  a  successive  co-operation.  For 
instance,  as  Professor  Bain  observes,  '  In  all  mantud  opera- 
tions there  occur  successions  of  movements  so  tirmly  asso- 
ciated, that  when  we  will  to  do  the  first,  the  rest  follow 
mechanically  and  unconsciously.  In  eating,  the  action  of 
opening  the  mouth  mechanically  follows  the  raising  of  the 

iworsel Although  the  learning  of  successions  of 

movements  involves  the  medium  of  sensation,  in  the  first 
instance,  yet  we  nuist  assume  that  there  is  a  power,  in  the 
system,  for  associating  together  movements  as  such."  In 
fact,  it  miglit  well  have  been  added,  there  is  such  a  power 
that  manilests  itself  long  before  the  dawn  of  any  of  the 
powers  of  the  "  will "  ;  it  is  as  true  of  the  polyp  as  of  the  man 
tiiat  "  in  eating,  the  act  of  opening  the  mouth  mechanically 
follows  the  raising  of  the  morsel." 

So  with  the  highest  or  most  abstract  powers  of  mind. 
For  abstractly \  merely  means  the  mental  dissociating  of 
qualities  from  objects,  and,  in  its  higher  phases,  blending 
these  qualities,  or  conceptions  of  them,  into  new  ideal  com° 
binations. 

Lastly,  just  as  innumerable  special  mechanisms  of  mus- 
cular co-ordinations  are  found  to  be  inherited,  innuraeiable 
special  associations  of  ideas  are  found  to  be  the  same ;  and  in 
one  case  as  in  the  other,  the  strength  of  the  organically 
nuposed  connection  is  found  to  bear  a  direct  proportion  to 
the  frequency  with  which  in  the  history  of  the  species  it  has 
occurred.  Thus,  the  simplest,  oldest,  and  most  constant 
ideas  relatmg  to  time,  space,  number,  sequence,  &c.,  may  be 
compared,  in  point  of  organic  integrity,  with  the  oldest  and 
most  indissolubly  associated  muscular  movements,  such  as 
tliose  concerned  in  breathing,  deglutition,  and  visceral 
niotions.  _  Again,  inherited  instincts  have  their  counterparts 
in  such  inherited  muscular  co-ordinations  as  are  not  abso- 

•  Principles  of  Psychology,  vol.  ii,  p.  476. 


44 


MENTAL  EVOLUTION  IN  ANIMALS. 


lutely  indissoluble.  And  similarly,  of  course,  associations  of 
ideas  acquired  only  during  the  life-history  of  the  individual 
need  to  be  more  or  less  constantly  maintained  by  repetition, 
just  as  muscular  co-ordinations  similarly  acquired  can  only 
be  maintained  by  practice. 

Upon  the  whole,  therefore,  it  is  impossible  that  there  could 
be  a  more  precise  parallelism  between  these  two  manifesta- 
tions of  nervous  machinery,  and  it  is  one  which  for  recog- 
nition in  a  general  way  does  not  require  scientific  analysis  ; 
it  has  been  perceived  by  the  common  sense  of  mankind — 
witness,  for  instance,  the  term  "  gymnastics  "  having  become 
applicable  to  mental  no  less  than  to  muscular  co-ordinations. 
But,  for  the  sake  of  systematic  completeness,  I  shall  conclude 
this  exposition  by  briefly  pointing  out  that  all  those  patho- 
logical derangements  which  occur  in  the  nervous  centres  that 
preside  over  muscular  activities,  have  their  parallels  in 
similar  derangements  which  occur  in  the  nervous  centres 
that  are  concerned  in  mental  activities.  Thus  "nervous- 
ness," or  a  disturbance  of  the  normal  balance  of  nerve- 
centres,  has  a  strikingly  analogous  effect  in  confusing  the 
ideas  and  in  perturbing  muscular  co-ordinations.  Idiotcy  has 
its  parallel  in  inability  to  perform  complex  muscular  move- 
ments, with  which  inability,  indeed,  idiotcy  is  itself  almost 
invariably  associated.  Lunacy  has  it  counterpart  in  an  un- 
balanced, or  badly  correlated  power  of  muscular  co-ordina- 
tion, which  in  its  graver  manifestations  is  known  as  ataxy ; 
while  mania  is  mental  convulsion,  and  unconsciousness 
mental  paralysis. 

I  must  not,  however,  take  leave  of  this  branch  of  our 
subject  without  briefly  alluding  to  a  difficulty  which  may 
occur  to  some  minds,  and  which  has  been  well  stated  by 
Professor  Calderwood  in  his  recently  published  work.*  The 
difficulty  to  which  I  allude  arises  from  there  being  an 
absence  of  such  a  constant  relationship  between  the  size  or 
mass  of  the  brain,  and  the  degree  of  intelligence  displayed 
by  it,  as  the  foregoing  teaching  would  reasonably  lead  us  to 
expect. 

Now,  I  do  not  deny  that  the  relation  of  intelligence  to 
size,  mass,  or  weight  of  brain  is  a  perplexing  matter  when 
we  look  to  the  animal  kingdom  as  a  whole ;  for  although 
there  is  unquestionably  a  general  relation  of  a  quantitative 

•  Pp.  211—216. 


THE  PHYSICAL  BASIS  OF  MIND. 


45 


kind,  it  is  not  a  constant  relation.  Even  within  the  limits  of 
the  human  species  this  relation  is  not  so  precise  as  is  usually 
supposed;  for,  neglecting  particular  cases  that  might  be 
quoted  of  men  of  genius  not  having  particularly  large  or 
heavy  brains,  the  converse  cases  are  perhaps  in  this  connec- 
tion more  remarkable— viz.,  those  of  feeble-minded  persons 
having  large  and  apparently  well-formed  brains.  I  am 
indebted  to  Dr.  Frederick  Bateman  of  the  Eastern  Counties' 
Asylum  for  directing  my  attention  to  the  observations  of 
Dr.  Mierzejewskis,  which  were  published  at  the  international 
congress  of  psychologists  held  in  Paris  in  1878.  These 
observations,  which  appear  to  have  been  carefully  made, 
seeing  that  casts  of  the  brains  were  exhibited,  went  to  show' 
that  idiotcy  is  compatible  with  large  and  apparently  well- 
developed  brains — the  amount  of  grey  matter  in  one  instance 
being  "  enormous." 

And,  if  we  turn  to  the  animal  kingdom,  we  find  in  a  still 
larger  measure  that  the  mere  amount  of  cerebral  substance 
furnishes  but  a  very  uncertain  index  of  the  level  of  intelli- 
gence which  is  attained  by  the  animal.  This  is  the  case 
even  when  we  eliminate  the  element  of  complexity  that  is 
introduced  by  the  differences  which  obtain  in  different 
animals  between  the  bulk  of  the  brain  and  the  bulk  of  the 
body— small  animals  requiring  a  greater  proportional  bulk  of 
brains  than  large  ones,  because  the  nervous  machinery  which 
ministers  to  muscular  movement  and  co-ordination  has  in 
both  cases  to  be  accommodated.  But  this  element  of  com- 
plexity may  be  removed  by  considering  the  cases  in  which 
small  animals  exhibit  remarkable  intelligence ;  and  in  this 
respect  no  animals  are  so  remarkable  as  the  more  intelligent 
species  of  ants  alluded  to  in  my  former  work.  As  Mr.  Darwin 
has  observed,  the  brain  of  such  an  insect  deserves  to  be 
regarded  as  perhaps  the  most  wonderful  piece  of  matter  in 
the  world. 

But  if  this  whole  question  touching  the  relation  between 
the  mass  of  brain  and  degree  of  intelligence  is  felt  to  lie  as 
a  difficulty  in  the  way  of  evolutionary  theory,  I  should  reply 
to  it  by  the  following  considerations. 

In  the  first  place,  that  there  is  a  general  relation  between 
size  of  brain  and  degree  of  intelligence,  both  in  the  case  of 
man  and  in  that  of  animals,  is  unquestionable.  It  is,  there- 
fore, only  with  the  more  special  exceptions  that  wc  iiave  to 


J 


111 


^ 


46 


MENTAL  EVOLUTION  IN  ANIMALS. 


deal.  But  here  we  have  to  remember  that  besides  size  or 
mass,  there  must  certainly  be  a  no  less  important  factor  to  be 
taken  into  account — that,  namely,  of  structure  or  complexity. 
Now  we  really  know  so  little  about  the  relations  of  intelli- 
gence to  neural  structure,  that  I  do  not  think  we  are  justified 
in  forming  any  very  strong  conclusions  d-  'priori  concerning  the 
relation  of  intelligence  to  mere  size  or  mass  of  brain.  Know- 
ing in  a  general  way  that  mass  plus  structure  of  brain  is 
necessary  for  intelligence,  we  do  not  know  how  far  the 
second  of  these  two  factors  may  be  increased  at  the  expense 
of  the  first.  And,  as  a  mere  matter  of  complexity,  or  of 
multum  in  parvo,  I  am  not  sure  that  even  the  brain  of  an 
ant  deserves  to  be  considered  more  wonderful  than  the  ovum 
of  a  human  being.  Lastly,  in  this  connection  it  may  be  as 
well  to  observe  that  there  is  as  good  evidence  to  show  the 
importance  of  cerebral  structure  as  a  factor  in  determining 
the  level  of  mental  development,  as  there  is  to  show  the 
importance  of  cerebral  mass.  Throughout  the  vertebrated 
series  of  animals  the  convolutions  of  the  brain — which  are 
the  coarser  expressions  of  more  refined  complexities  of 
cerebral  structure — furnish  a  wonderfully  good  general  indi- 
cation of  the  level  of  intelligence  attained ;  while  in  the 
case  of  ants  Dujardin  says  that  the  degree  of  intelligence 
exhibited  stands  in  an  inverse  proportion  to  the  amount  of 
cortical  substance,  or  in  direct  proportion  to  the  amount  of  the 
peduncular  bodies  and  tubercles.  In  view  of  these  con- 
siderations, therefore,  I  do  not  feel  that  the  supposed  diffi- 
culty, which  I  have  thought  it  desirable  to  mention,  is  one  of 
any  real  solidity. 


THE  ROOT-rKINCIPLES  OF  MIND. 


47 


CHAPTER  IV. 


The  Eoot-principles  of  Mind. 

Although  the  phenomena  of  Mind,  and  so  of  Choice,  are 
both  complex,  and  as  to  their  causation  obscure,  I  think  we 
have  now  seen  that  we  are  justified  in  beheving  that  they  all 
present  a  physical  basis.      That  is  to  say,  whatever  opinion 
we  may  happen  to  entertain  regarding  the  ultimate  nature  of 
these  phenomena,  in  view  of  the  known  facts  of  physiology 
we  ought  all  to  be  agreed  concerning  the  doctrine  that  the 
mental  processes  which  we  cognize  as  subjective,  are  the 
psychical  equivalents  of  neural  processes  which  we  recofr- 
mze  as  objective.      As  already  stated,  I  have  elsewhere  con- 
sidered the  various  hypotheses  concerning  the  nature  and  the 
various  attempts   at    an    explanation   of    this   equivalency 
between  mental  processes  and  neural  processes ;   but  here  I 
desire  to  consider  the  fact  of  this  equivalency  merely  as  a 
fact      It  will  therefore   signify  nothing  to  my  discussion 
whether,  with  the  materialists,  we  rest  in  this  fact  as  final  or 
endeavour,  with  men  of  other  schools,  to  seek  an  explanation 
ot  the  tact  of  some  more  ultimate  character.      It  is  enouoh 
if  we  are  agreed  that  every  psychical  change  of  which  we 
have  any  experience  is  invariably  associated  with  a  definite 
physical  change,  whatever  we  may  suppose  to  be  the  nature 
and  significance  of  this  association. 

Looking,  then,  at  the  phenomena  of  Mind  as  invariably 
presenting  a  physical,  or,  as  we  may  indifferently  call  it  a 
physiological  side,  I  shall  endeavour  to  point  out  what  I  con- 
ceive to  be  the  most  ultixnate  principle  of  physiology  which 
analysis  shows  to  be  common  to  them  all.  On  the  mental 
side,  as  we  have  already  seen,  we  have  no  difficulty  in  dis- 
tinguishing this  ultimate  principle,  or  common  characteristic 
as  that  which  we  designate  by  the  term  Choice.  Now  if  the 
power  of  choice  is  the  distinctive  peculiarity  of  a  mental 


m 


'  i 


iB 


MENTAL  EVOLUTION  IN  ANIMALS. 


I! 


being,  and  if.  as  we  have  taken  for  granted,  every  chancre  of 

latPdlnti  '     '  ^'''^T^y  ought  to  admit  of  being  trans- 
ated  into  some  pliysiological  equivalent.      Further  if  there 

exZJtfnJ^^r^''^T}  ^^^i^lent  to  be  found,  we  should 
expect  to  fina  it  much  lower  down  in  the  scale  of  physio- 
logical development  than  in  the  functions  of   the  human 

W  ;i  r''''*  ^"i^^  ^^  *^^  ^^^^'^  ^^i«^al«  manifest,  in  a 

long  descending  scale,  powers  of  choice  which  gradually  fade 

leT^'.'l.^T'''  ^"^  ^n^r  shn^lioity;  but^e  should  be 
Led  d  prion  to  expect,  if  there  is  a  physiolocrical  nrincinle 
which  constitutes  the  objective  basis%f  the^psycSoS 
principle,  that  t^ie  former  should  manifest  itself  more  early 
m  the  course  of  evolution  than  the  latter.  Tor,  whatever 
InTlr^^i  ";?^  entertain  concerning  the  relation  of  Body 
pvnl  ^^'^^V,^^^^^  «?n  be  no  question,  on  the  basis  of  the 
eyolu  ion  theory  which  I  assume,  thai,  as  a  matter  of  his! 

tW  n/'^"'''f 'i^^'  P^^^^Plf  of  physiology  were  prior  to 
those  of  psychology;  and  therefore,  if  in  accordance  with 
our  original  agreement  we  allow  that  the  latter  have  a  phv- 
sical  basis  m  the  former,  it  follows  that  the  principles  of 

Now  I  think  that  the  d  priori  expectation  thus  briefly 
sketched  IS  fully  realized  in  the  occurrence  of  a  physiologic^ 
principle,  which  first  appears  very  low  down  in  the  worfd  of 
lite,  and  which,  in  its  relation  to  psychology,  has  not  yet 
received  the  attention  which  it  desen4      f  Ly  best  state 
the  principle  by  giving  an  example.     I  have  observed  that  if 
a  sea-anemone  is  placed  in  an  aquarium  tank,  and  allowed 
to  fasten  upon  one  side  of  the  tank  near  the  surface  of  the 
water  and  if  a  jet  of  sea  water  is  made  to  play  continuously 
and  forcibly  upon  the  anemone  from  above,  the  result  of 
course  is  that  the  animal  becomes  surrounded  with  a  turmoil 
of  water  an^  air-bubbles.     Yet,  after  a  short  time,  it  becomes 
80  accustomed  to  this  turmoil  tliat  it  will  expand  its  tentacles 
in   earch  ot  food,  just  as  it  does  when  placed  in  calm  watei' 
If  now  one  of  the  expanded  tentacles  is  gently  touched  with 
a  solid  body,  all  the  others  close  around  that  body,  in  iust 
the  same  way  as  they  would  were  they  expanded    n  calm 


THE  ROOT-PRINCIPLES  OF  MIND.  49 

of  the  water  and  tS  whiVh  t  TJ'\^  ^^  ^^^  turmoil 
with  the  solid  My^e^attrL'St^^^^^^  '.^^^  ^^^-^ 
notwithstanding^  that  it  :'z.f  -^  ^^  ,  ^  ^'^"^r  stimulus 
than  the  former  And  ii  i.  f^''''''"^'''^^^  ^^««  ^^^^n^ity 
between  stimulf^Vrti^^  ^7''  of  discriminating 

sities,  that  I  re^ird  afthrohl         '"'•^''''•'^^  ''Mechanical  Intel 
in  search  ;  it  Stutes  the  SlinF""T^'  "^  ^^^^^  ^^  ^^^e 

A  similar  power  of  discriSn!^''"^  ^'P'?  ^^  ^^^^°i^«- 
known  to  occur  in  Xnts  thZr. l  "''P^^'"  ^"«  ^^"S  been 
facts  with  regard  to  ll'-„\S^  "^^.^  ^^^^"7  observed 
we  owe  to  the  later  rZ^^Tr^l^^t^^  ^^^"^^^ 
-The  extraordinary  dehV-nv  nf  .r  •  .  ^y^^  ^nd  his  son. 
researches  show  the  S  of  t^^TT''"''  ^^"^^  ^^^^«« 
darkness  and  light  of  the  feebW  i  ^  '^f''^?"  ^^^^^^^^ 
wonderful  than  the  delicn^v  nf  ^       .intensity,  is  not  less 

show  the  roots  of  i^^J:^^  eL'rd^ITSn  "'^l^'  '""t^ 
moisture  and  lines  of  least  rp.icf.!^    •    1      ""^  «  ^^out  for 
present  connection  the  most  si. S".  '"^  f"^  '°^^-     ^^^  ^^  the 
have  been  brought    0  Tio  it  bf  Mr ''ti  '''  '>''  '^°^^  ^^^^^^^ 
searches  on  the dimbim^   nnd   ,'        .^'"^^^^^^  Previous  re- 
from  these  researches  it  ^^^^^  that  theT"  ^^"'^     ^°^' 
nating  between  stimuli,  inSpective  of  iT''  '^  ^^f  ""^^- 
mtensity  or  amount  o    niechan  cal   rLf  f  "^^  mechanical 
proceeded  to  an  extent  tW  rlf/f  .1^  '^."'^''"^®'   ^^^  here 
tissue,  although  tSltu^VhS^^rirh  ''  ""''''' 
structure  passed  beyond  the  cell,  l«r^f  mu  ^''''^  ^°<^  ^^ 

eles  of  Drosera,   4ich  2sp   ijf  'JT^'  .  Thus,  the  tenta- 
tentaoles  of  a  seaTnemone  will  "^^^^^  '^  ^'"^  ^'^''  ^^'^ 

stimulation  supplied  TyTai^m  '"  ^}'  ^^°^«"<^ 

Ji.--f-sor'.Slands,;irttT^^^^^^^ 
ceivably  slight  stimulus  of  the  kindmsed  hv  nl      ^  T""'" 
mmute  particle  of  solid  matter  exert  n!b/       "^:i'^^^^^««l3' 
tmuous  pressure  upon  the  samp  ff^J'^'"^  by  gravity  a  con- 
says,  "Thepressurretted  rTptSie  oM  ''^-  ^'T^^ 
only  T^  of  a  grain,  and  sup^rt^ed  w  a  de^^^^^^^  ""^'^^'^""^ 
have  been  mconceivablv  sli-^bf       w?  ^        ^^  ^"^^'  ""^^t 
could  hardly  have  equ  (led  Ihe  milwr^/'^J'"-^"^*^  ^^'^^  i<^ 
shall  hereafter  see  that  f,r  lei  ^^   ?^^  of  a  gram  ;  and  we 
of  phosphate  of  ammonia  in  so t^n     '  T^^''"^'^'  '^  ^  ^rain 
gland,  acts  on  it  aTd^Uicef  iTJe'r  ''''''''  i^/  -^ 

'      •      •      •      XL    IS 


-I 


50 


MENTAL  EVOLUTION  IN  ANIMALS. 


extremely  doubtful  whether  any  nerve  in  the  human  body, 
even  if  in  an  inflamed  condition,  would  be  in  any  way 
affected  by  such  a  particle  supported  in  a  dense  fluid,  and 
slowly  brought  into  contact  with  the  nerve.  Yet  the  cells 
of  the  glands  of  Drosera  are  thus  excited  to  transmit  a 
motor  impulse  to  a  distant  point,  inducing  movement.  It 
appears  to  me  that  hardly  any  more  remarkable  fact  than 
this  has  been  observed  in  the  vegetable  kingdom. '         ^ 

But  the  case  does  not  end  here.      For  m  another  insec- 
tivorous plant,  Dionoea,  or  Venus'  Fly-trap,  the  principle  of 
discriminating  between  different  kinds  of  stimuh  has  been 
developed  in  a  direction  exactly  the  opposite  to  that  which 
obtains  in  Drosera.   For  while  Drosera  depends  for  captunng 
its  prey  on  entangUng  the  latter  in  a  viscid  secretion  from  its 
olands,  Dionoea  closes  upon  its  prey  with  the  suddenness  of 
a  spring-trap;  and  in  relation  to  this  difi'erence  m  the  mode 
of  capturing  prey,  the  principle  of  discrimination  between 
stimuli  has  been  correspondingly  modified.    In  Drosera,  as  we 
have  seen,  it  is  the  stimulus  supplied  by  oontinuous  pressure 
that  is  so  delicately  perceived,  while  the  stimulus  supphed 
by  ivipact  is  disregarded;  but  in  Dionoea  the  smallest  impact 
upon  the  irritable  surfaces,  or  filaments,  is  immediately  re- 
sponded to,  while  the  stimulus  supplied  even  by  compara- 
tively great  pressure  upon  the  same  surfaces  is    wholly 
disregarded.     Or,  in  Mr.  Darwin's  own  words,  "  Although  the 
filaments  are  so  sensitive  to  a  momentary  and  delicate  touch, 
they  are  far  less  sensitive  than  the  glands  of  Drosera  to  pro- 
longed pressure.     Several  times  I  succeeded  m  placing  on 
the  tip  of  a  filament,  by  the  aid  of  a  needle  moved  with 
extreme  slowness,  bits  of  rather  thick  human  hair,  and  these 
did  not  excite  movement,  although  they  were  more  than  ten 
times  as  long  as  those  which  caused  the  tentacles  of  Drosera 
to  bend ;  and  although  in  this  latter  case  they  were  largely 
supported  by  the  dense  secretion.      On  the  other  hand  the 
olands  of  Drosera  may  be  struck  with  a  needle,  or  any  hard 
Sbiect,  once,  twice,  or  even  thrice,  with  considerable  force, 
and  no  movement  ensues.     This  singular  difference  in  the 
nature  of  the  sensitiveness  of  the  filaments  of  Dionoea  and 
of  the  glands  of  Drosera  evidently  stands  in  relation  to  the 
habits  of  the  two  plants.     If  a  minute  insect  alights  with  its 
delicate  feet  on  the  glands  of  Drosera,  it  is  caught  by  the 
viscid  secretion,  and  the  slight,  though  prolonged  pressure 


THE  ROOT-PRINCIPLES  OF  MIND. 


51 


gives  notice  of  the  presence  of  prey,  which  is  secured  by  the 
slow  bending  of  the  tentacles.  On  the  other  hand,  the  sensi- 
tive filaments  of  Dioncea  are  not  viscid,  and  the  capture  of 
insects  can  only  be  assured  by  their  sensitiveness  to  a 
momentary  touch,  followed  by  the  rapid  closure  of  the  lobes." 
So  that  in  these  two  plants  the  power  of  discriminating 
between  these  two  kinds  of  stimuli  has  been  developed  to  an 
equally  astonishing  extent,  but  in  opposite  directions. 

But  we  find  definite  evidence  of  this  power  of  discrimina- 
tive selection  even  lower  down  in  the  scale  of  life  than  the 
cellular  plants;  we  find  it  even  among  the  protoplasmic 
organisms.  Thus,  to  quote  an  instructive  case  from  Dr.  Car- 
penter : — 

"  The  Deep-Sea  researches  on  which  I  have  recently  been 
engaged  have  not '  exercised  '  my  mind  on  any  topic  so  much 
as  on  the  following : — Certain  minute  particles  of  living  jelly, 
having  no  visible  differentiation  of  organs  ....  build 
up  '  tests '  or  casings  of  the  most  regular  geometrical  sym- 
metry of  form,  and  of  the  most  artificial  construction  .  .  . 
From  the  same  sandy  bottom,  one  species  picks  up  the  coarser 
quartz-grains,  cements  tliem  together  with  phosphate  of  iron 
(?),  which  must  be  secreted  from  their  own  substance ;  and 
thus  constructs  a  flask-shaped  '  test '  having  a  short  neck  and 
a  single  large  orifice.  Another  picks  up  iho.  finer  grains,  and 
puts  them  together  with  the  same  cement  into  perfectly 
spherical  '  tests '  of  the  most  extraordinary  finish,  perforated 
with  numerous  small  tubes,  disposed  at  pretty  regular  inter- 
vals. Another  selects  the  minutest  sand-grain  and  the 
terminal  points  of  sponge-spicules,  and  works  these  up 
together — apparently  with  no  cement  at  all,  but  by  the 
'  laying '  of  the  spicules — into  perfect  spheres,  like  homceo- 
pathic  globules,  each  having  a  single  fissured  orifice."  * 

Thus,  co-extensive  with  the  phenomena  of  excitability, 
that  is  to  say,  with  the  phenomena  of  life,  we  find  this  func- 
tion of  selective  discrimination  ;  and,  as  I  have  said,  it  is  this 
function  that  I  regard  as  the  root-principle  of  Mind.  I  so 
regard  it  because,  if  we  consider  all  the  faculties  of  mind,  we 
shall  observe  that  the  one  feature  which  on  their  objecix  .'e 
side  they  present  as  common,  is  this  power  of  discriminating 
among  stimuli,  and  responding  only  to  those  which,  irrespec- 
tive of  relative  mechanical  intensity,  are  the  stimuli  to  which 
*  Coniem^orari/  Review,  April,  1873 


!1 


' — ^--yi — rni-J 


I   : 


ill 


62 


MENTAL  EVOLUTION  IN  ANIMALa 


responses  are  appropriate.  In  order  to  see  this,  let  tis  lake 
the  principal  faculties  of  mind  in  their  ascending  order,  and 
consider  what  they  are,  in  their  last  analysis,  upon  their 
physiological  side.  First  we  have  the  organs  of  special 
Sensation,  the  physiological  functions  of  which  clearly  con- 
stitute the  basis  of  the  whole  structure  psychological.  Yet 
no  less  clearly,  these  functions  in  their  last  analysis  are 
merely  so  many  specially  developed  aptitudes  of  response  to 
special  modes  of  stimulation.  Thus,  for  instance,  the  struc- 
ture of  the  eye  is  specially  adapted  to  respond  only  to  the 
particular  mode  of  stimulation  that  is  supplied  by  light,  the 
ear  to  that  which  is  supplied  by  sound,  and  so  on.  In  other 
words,  the  organs  of  special  sense  are  so  many  structures 
]  which  have  been  variously  and  extremely  differentiated  in 
several  directions,  for  the  express  purpose  of  attaining  a 
severally  extreme  sensitiveness  to  special  modes  of  stimula- 
tion v/.'thout  reference  to  any  other  mode.  And  this  is 
merely  to  say  that  the  function  of  an  organ  of  special  sense 
is  that  of  sorting  out,  selecting,  or  discriminating  the  par- 
ticular kind  of  stimulation  to  which  its  responsive  action  is 
appropriate. 

Again,  many  of  the  nervous  mechanisms  which  minister  to 
various  Eeflex  Actions  are  only  thrown  into  activity  by  special 
modes  of  stimulation.  This  is  notably  the  case  with  those  highly 
complicated  neuro-muscular  mechanisms  which  are  thrown 
into  activity  only  by  the  mode  of  stimulation  which  we  call 
tickling.  Such  instances  are  of  special  interest  in  the  present 
connexion  from  the  fact  that  the  distinguishing  peculiarity  of 
this  mode  of  stimulation  consists  in  its  being  a  stimulation  of 
low  intensity.  The  comparatively  violent  stimulation  that  is 
caused  by  the  passage  of  food  down  the  gullet,  or  by  contact 
of  the  soles  of  the  feet  with  the  ground,  is  unproductive  of 
any  response  on  the  part  of  the  mechanisms  which  are 
thvown  into  violent  activity  by  the  gentlest  possible  stimula- 
tion of  the  same  surfaces.  Similarly  with  regard  to  Instincts. 
These,  physiologically  considered,  are  the  activities  of  highly 
differentiated  nervous  mechanisms  which  have  been  slowly 
elaborated,  through  successive  generations,  for  the  express 
purpose  of  responding  to  some  particular  stimulus  of  a  higlily 
wrought  character,  and  which,  on  its  psychological  side,  is  a 
recognition  of  the  circumstances  to  which  the  instinctive 
adjustment  is  appropriate.    And  so  with  the  Emotions.    Tor, 


THE  ROOT-PRINCIPLES  OF  MIND 


63 


physiologically  considered,  the  emotions  are  the  activities  of 
highly  wrought  nervous  mechanisms,  and  these  activities  are 
only  excited  by  the  very  special  stimuli  which,  on  their  sub- 
jective side,  we  recognize  as  the  particular  kind  of  ideas 
which  are  appropriate  to  call  up  particular  emotions.    We 
do  not  laugh  at  a  painful  sight,  nor  does  a  ludicrous  sight 
cause    us  to  weep;    and    this,  physiologically  considered, 
merely  means  that  the  nervous  machinery  whose  action  is 
accompanied  by  one  emotion,  will  only  respond  to  one  kind  of 
very  specialized  and  complex  stimulation  ;  it  will  not  respond 
to  another  and  probably  in  many  respects  very  similar  kind  of 
stimulation,  which,  nevertheless,  is  competent  to  evoke  re- 
sponses from  another  and  probably  very  similar  piece  of  nervous 
machinery.    And  thus,  also,  it  is  with  Eeasoning  and  Judg- 
ment.    Eeasoning,  on  its  physiological  side,  is  merely  a  series 
of  highly  complicated  nervous  changes,  regarding  which  the 
only  thing  we  certainly  know  is,  that  not  one  of  them  can 
take  place  without  an  adequate  physical  accompaniment,  and 
therefore  that  on  its  physiological  side  a  train  of  reasoning  is 
a  series  of  nervous  changes,  every  one  of  which  must  be 
produced  by  physical  antecedents.     And  hence  on  its  objec- 
tive side  every  step  in  a  train  of  reasoning  consists  in  a 
selective  discrimination  among  all  those  exceedingly  delicate 
stimuli  which,  on  their  subjective  side,  we  know  as  argu- 
ments.    Similarly  regarded.  Judgment  is  likewise  nothing 
more  than  the  final  result  of  the  incidence  of  a  vast  number 
of  very  delicate  stimuli ;  and  this  final  result,  like  all  the 
intermediate  steps  of  the  reasoning  which  led  to  it,  is  nothing 
more  than  the  exercise  of  a  power  to  discriminate  between 
the  stimulus  which  on  its  subjective  side  we  recognize  as  the 
right,  and  that  which  we  similarly  recognize  as  the  wrong. 
Lastly,  Volition,  subjectively  considered,  is   the  faculty  of 
consciously  selecting  motives ;  and  motives,  objectively  con- 
sidered,  are  nothing    more  than  immensely  complex   and 
inconceivably  refined  stimuli  to  nervous  action. 

If  we  turn  from  the  ascending  scale  of  mental  faculties 
in  man,  to  the  ascending  scale  of  mind  in  the  animal  king- 
dom, we  shall  meet  with  further  and  still  more  definite  evi- 
dence that  the  distinguishing  property  of  mind,  on  its 
physiological  side,  consists  in  this  power  of  discriminating 
between  different  kinds  of  stimuli,  irrespective  of  their 
degrees  of  mechanical  intensity.    But,  before  giving  a  brief 


I 


11 


1   I 


54 


MENTAL  EVOLUTION  IN  ANIMALS. 


review  of  the  evidence  on  chis  point,  I  may  here  meet  a 
difficulty  which  has  already  arisen.    The  difficulty  is  that  1 
began  by  showing  it  necessary  to  define  Mind  as  the  power 
of  exercising  Choice,  and  then  proceeded  to  define  the  latter 
as  a  power  belonging  only  to  agents  that  are  able  to  teel. 
Yet,  on  looking  at  the  objective  side  of  the  prob  era    1 
pointed  out  that  the  physiological  or  objective  equivalent  ot 
Choice  is  found  to  occur  in  its  simplest  manifestations  at 
least  as  low  down  as  the  insectivorous  plants  which  are 
certainlv  not  agents  capable,  in  any  proper  sense  of  the  term, 
of  feelincT.    Therefore  it  seems  that  my  conception  ot  what 
constitutes  Choice  is  in  antagonism  with  my  view  that  the 
essential  element  of  Choice  is  found  to  occur  among  organ- 
isms which  cannot  properly  be  supposed  to  feel.    And  this 
antagonism,  or  inherent  contradiction,  is  a  real  one.  though  I 
hold  it  to  be  unavoidable.     For  it  arises  from  the  fact  that 
neither  Feeling  nor  Choice  appears  upon  the  scene  ot  lite 
suddenly.    We  canaot  say,  within  extensive  limits    where 
either  can  properlj'  be   said  to  begin.    They  both   dawn 
eraduaUy,  and  therefore  in  our  everyday  use  ot  these  terms 
we  do  not  wait  to  consider  where  they  are  first  applicable; 
we  only  apply  them  where  we  see  their  applicability  to  be 
apparent.     But  when  we  endeavour  to  use  these  same  terms 
in  strict  psychological  analysis,  we  are  at  once  met  with  the 
difficulty  of  drawing  the  line  where  the  terms  are  applicable 
and  where  they  are  not.    There  are  two  ways  of  meeting  the 
difficulty.     One  is  to  draw  an    rbitrary  line,  and  the  other  is 
not  to  draw  any  line  at  all;  but  to  carry  the  terms  down 
through  the  whole  gradation  of  the  things  until  we  arrive  at 
the  te°rminal  or  root-principles.   By  the  time  that  we  do  arrive 
at  these  root-principles,  it  is  no  doubt  true  that  our  terms  have 
lost  all  their  original  meaning ;  so  that  we  might  as  well  call 
an  acorn  an  oak,  or  an  egg  a  chicken,  as  speak  of  a  Dioncea 
feeMna  a  fly,  or  of  a  Drosera  cJwosing  to  close  upon  its  prey. 
Yet  this  use,  or  rather  let  us  call  it  abuse,  of  terms  serves  one 
important  purpose  if,  while  duly  regarding  the  change  of 
meaning  which  during  their  gradual  descent  the  terms  are 
made  gradually  to  undergo,  we  thus  serve  to  emphasize  the 
fact  that  they  refer  to  things  which  are  the  product  of  a 
gradual  evolution-things  which  came  from  other  things  as 
unlike  to  them  as  oaks  to  acorns  or  chickens  to  eggs.     And 
this  is  my  justification  for  tracing  back  the  root-prmciples  of 


THE  ROOT-PRINCIPLES  OF  MIND. 


65 


Feeling  and  of  Choice  into  the  vegetable  kingdom.  If  it  ia 
true  that  plants  manifest  so  little  evidence  of  Feeling  that 
the  term  can  only  he  applied  to  them  in  a  metaphorical  sense, 
it  is  also  true  that  the  power  of  Choice  which  they  display  is 
of  a  similarly  undeveloped  character ;  it  is  limited  to  a  single 
act  of  discrimination,  and  therefore  no  one  would  think  of 
applying  the  term  to  such  an  act,  until  analysis  reveals  that 
in  such  a  single  act  of  discrimination  we  have  the  germ  of 
all  volition. 

Let  it  therefore  be  understood  that  the  difficulty  which 
we  are  considering  arises  merely  from  the  gradual  manner  in 
v'^-lch  the  faculties  in  question  u,ose.  The  rudimentary 
power  of  discriminative  excitability  which  a  plant  dispKays 
is  commensurate  with  the  rudimentary  power  of  selective 
adjustment  which  it  manifests  in  its  movements  ;  and,  just  as 
the  one  is  destined  by  developmental  elaboration  to  become  a 
self-conscious  subjectivity,  so  the  other  is  destined,  by  a 
similar  elaboration,  to  become  a  deliberative  volition. 

I  shall  now  briefly  glance  at  the  ascending  scale  of 
organisms,  with  the  view  of  showing  that  this  proportional 
relation  between  the  grade  of  receptive  and  that  of  executive 
ability  is  manifested  throughout  the  series.  I  desire  to  makti 
it  plain  that  the  power  of  discrimination  which  in  its  higher 
manifestations  we  recognize  as  Feeling,  and  the  power  of 
selective  adjustment  which  in  its  higher  manifestations  we 
recognize  as  Choice,  are  developed  together,  and  throughout 
their  development  are  commensurate. 

Amoeba  is  able  to  distinguish  between  nutritious  and  non- 
nutritious  particles,  and  in  correspondence  with  this  one  act 
of  discrimination  it  is  able  to  perform  one  act  of  adjustment ; 
it  is  able  to  enclose  and  to  digest  the  nutritious  particles, 
while  it  rejects  the  non-nutritious.  Some  protoplasmic  and 
unicellular  organisms  are  a'3le  also  to  distinguish  between 
light  and  darkness,  and  to  adapt  their  movements  to  seek  the 
one  and  shun  the  other ;  while  in  "  Animal  Intelligence  " 
some  observations  are  given  which  seem  to  show  that  the 
discriminative  and  adjustive  powers  of  these  organisms  may 
go  farther  even  than  this.  The  insectivorous  plants,  as  we 
have  already  seen,  are  able  to  distinguish,  not  only  between 
nutritious  and  non-nutritious  particles,  but  also  between 
different  kinds  of  contact ;  and,  in  corresponc.ence  with  this 
advance  in  receptive  power,  we  observe  a  commensurate 


66 


MENTAL  EVOLUTION  IN  ANIMALS. 


■7 


/ 


I 


^^  \ 


advance  in  the  mechanism  of  adaptive  movement.     Numhor- 
leas  other  cases  of  such  simple  powers  among  plants  might 
here  be  noticed ;  but  none  of  thera  rise  above  the  level  of 
distinguishing  between  one  or  two  alternatives  of  stimula- 
tion, and  supplying  the  correspondingly  simple  movements 
of  response.     Where   nerve-structure  first  appears,  we  find 
that  the  animals  wliich  present  it — the  Medusa) — have  organs 
of  special  sense  whorewith  to  distinguish  with  comparative 
delicacy  and    rapidity  between    light    and    darkness,  and 
probably  also  between  sound  and   silence.     They  are  also 
provided  with  an  elaborate  tentacular  apparatus,  wherewith 
they  are  able  to  distinguish  quickly  and  accurately  between 
moving  and  not  moving  objects  coming  upon  them  from 
various  sides,  as  well  as  between  nutritious  and  non-nutri- 
tious particles.     And  in  con-espondence  with  this  advance  of 
receptive   capacity  we  observe   a  considerable  advance  of 
executive  capacity — the  animals  being  highly  locomotive, 
swimming  away  rapidly  from  sources  of  contact  which  they 
distinguish  as  dangerous,  and  manifesting  several  other  retlex 
actions  of  a  similarly  adaptive  kind.     Tims,  also,  the  higher 
organizations  of  Star-fish,  Worms,  &c.,  wh.ile  serving  to  supply 
the   neuro-muscular    mechanisms  with  still  more  detailed 
information  regarding  the   outer  world,   serve  likewise  to 
supply  them  with  the  means  of  executing  a  greater  variety 
of  adaptive  movements.     In  the  Mollusca,  again,  we  observe 
another  advance  in  both  these  respects;  the  animals  feel 
their  way  with  sensitive  feelers,  select  varied  kinds  of  food, 
choose  mates  of  their  own  species  to  pair  with,  and  may  even 
remember  a  particular  locus  as  their  home,  &c.    Among  the 
Articulata  the  lower  forms  present  co-ordinated  movements 
which  are  few  and  simple  as  compared  with  the  many  and 
varied  movements  of  the  higher  members  of  the  class ;  and 
their  powers  of  distinguishing  between  stimuli  are  propor- 
tionally small.     But  in  the  complicated  anatomy  of   the 
Crabs  and  Lobsters  there  is  a  large  provision  for  the  co-ordina- 
tion of  movements,  and  the  selective  actions  are  correspond- 
ingly nifinerous  and  varied;   while  among  the  Insects  and 
Spiders  the  power  of  muscular  co-ordination  surpasses  that 
of  the  lower  Vertebrata,  and  the  power  of  intelligent  adapta- 
tion, assisted  by  delicate  antennas  and  highly  perfected  organs 
of  special  sense,  is  also  greater.     And  the  same   principles 
hold  throughout  the  Vertebrated  series.    It  has  already  been 


THE  ROOT-PRINCIPLES  OF  MIND. 


87 


rpmnrkcd  by  Mr.  Spencer  that  there  is  here  a  general  corre- 
Bpondenco  to  be  observed  between  the  possession  of  organs 
capable  of  varied  actions,  and  the  degree  of  intelligence  to 
wliich  the  a,ninial  attains.  Tims  of  Birds  the  Parrots  are  the 
most  intelligent,  and  they,  more  than  any  other  members  of 
their  class,  are  able  to  use  tlieir  feet,  beaks,  and  tongues  in  tlie 
examination  of  objects.  Similarly,  the  wonderful  intelligence 
of  the  Elephant  may  be  safely  considered  as  correlated  with 
the  no  less  wonderful  instrument  of  co-ordinated  movement 
which  he  possesses  in  his  trunk  ;  while  the  superior  intelli- 
gence of  the  Monkey,  and  the  supreme  intelligence  of  Man 
may  no  less  safely  be  considered  as  correlated  with  the  ^ill 
more  wonderful  instrument  of  co-ordinated  movement  which 
has  attained  to  almost  ideal  perfection  in  the  human  liand. 
Again,  and  more  generally,  we  may  say  that  throughout  the 
animal  kingdom  the  powers  of  siglit  and  of  hearing  stand  in 
direct  ratio  to  the  powers  of  locomotion ;  and  the  latter  are 
conducive  to  the  growth  of  intelligence.* 

We  may  now  observe  that  this  correlation  between 
muscular  and  mental  evolution — or,  more  generally,  between 
power  of  discrimination  and  variety  of  adaptive  movements 
— is  only  what  we  should  expect  to  find  d  priori.  For  it  is 
clear  that  the  development  of  the  one  function  could  be  of  no 
use  without  that  of  the  other.  On  the  one  hand,  it  would  be 
of  no  use  to  an  organism  that  it  should  be  able  to  discern  a 
stimulus  as  hurtful  or  beneficial,  if  at  the  same  time  it  lacked 
the  power  of  co-ordinated  movement  necessary  to  adapting 
itself  to  the  result  of  its  discernment ;  and,  on  the  other 
hand,  it  would  be  equally  useless  that  an  organism  should 
possess  the  needful  power  of  co-ordinated  movement,  if  at 
the  same  time  it  lacked  the  power  of  discernment  which 
alone  could  render  the  power  of  co-ordinated  movement  use- 
ful. Now  we  know  that  all  the  meclianisms  of  muscular 
co-ordination  are  correlated  with  mechanisms  of  nervous  co- 
ordination, and,  indeed,  that  the  former  without  the  latter 
would  be  utterly  useless.    Yet  we  know  next  to  nothing  of 

•  The  Dog  and  Cat  seem  at  first  sight  to  constitute  an  exception  to  the 
principle  above  set  forth;  but  it  must  be  remembered  that  both  these 
animals,  and  all  tlieir  tribe,  possess  very  efficient  instruments  of  touch  and 
movements  in  their  tongues,  lips,  and  jaws,  as  well  as  to  some  extent  in  the 
paws.  I  think  the  superior  intelligence  of  tlie  Octopus,  among  molluslts,  is 
to  be  attributed  to  the  exceptional  advantages  which  are  rendered  by  its  large 
and  flexible,  sensitive  and  powerful  arms. 


n\ 


;if 't: 


i ) 


Vt    -li 


53 


MENTAL  EVOLUTION  IN  ANIMALS, 


i  :? 


J         ':': 


-7 


>•'! 


the  ultimate  nervous  mechanisms  whicli  play  down  upon  the 
muscular  mechanisms;  we  only  see  a  mazy  mexus  of  cells 
and  fihres,  the  very  function  of  which,  much  less  their  inti- 
mate mechanism,  could  not  be  guessed,  were  it  not  that  wo 
have  the  grosser  mechanisms  of  the  muscular  system  whereby 
to  study  the  effects  of  these  finer  mechanisms. 

Muscular  co-ordinations,  then,  are  so  many  indices,  "  writ 
large,"  of  corresponding  co-ordinations  taking  place  in  the 
nervous  system.  Now  we  have  seen  that  mental  processes 
may  be  regarded  as  indices  in  precisely  the  same  way,  and 
indeed  that,  like  muscular  movements,  they  are  the  only 
indices  we  have  of  the  operations  of  the  nervous  mechanisms 
with  which  they  are  connected.  Moreover,  we  have  seen 
that  when  this  new  set  of  indices  has  reached  a  certain  level 
of  development,  marking  of  course  a  corresponding  level 
of  development  in  the  nervous  system,  it  begins  unmistake- 
ably  to  show  that  the  functions  of  receptive  discrimination 
and  of  adaptive  movement  are  taking  yet  another  point  of 
departure  in  the  upward  course  of  their  development — that 
the  nervous  system  is  beginning  to  discriminate  between 
novel  and  enormously  complex  stimuli,  having  reference  not 
only  to  immediate  results,  but  also  to  remote  contingencies  ; 
we  see  in  short  that  the  nervous  mechanism  is  beginning  to 
develope  those  higher  functions  of  discriminative  and  adaptive 
ability  which  on  their  subjective  side  we  know  as  rational. 

Therefore  it  is  clear  that  these  two  faculties  not  only  do 
but  must  proceed  together.  Every  advance  in  the  power  of 
discrimination  will  be  followed,  in  the  life  of  the  individual 
and  in  that  of  the  species,  by  efforts  towards  the  movements 
of  needful  adaptation,  and  in  all  cases  where  such  movements 
require  an  advance  on  the  previous  power  cf  co-ordination, 
such  advance  will  be  favoured  by  natural  selection.  Thus 
every  advance  in  the  power  of  discrimination  favours  an 
advance  of  the  power  of  co-ordination.  And,  conversely,  we 
may  now  remark  that  every  advance  in  the  power  of  co- 
ordination favours  an  advance  of  the  power  of  discrimina- 
tion. For,  as  a  greater  pov^er  of  co-ordinated  movement 
implies  the  bringing  of  nerve-centres  into  new  and  more 
varied  relations  with  the  outer  world,  there  is  thus  afforded 
to  the  nerve-centres  a  proportionately  increa,sed  opportuni;.}' 
of  discrimination— an  opportunity  which  will  sooner  or  later 
be  sure  to  be  utilized  by  natural  selection. 


THE   ROOT-PRINCIPLES   OF  MIND. 


59 


Thus  the  two  facvlties  are,  as  it  were,  necessarily  bound 
together.     But  here  another  consideration  arises.     They  are 
thus  bound  together  only  up  to  the  point  at  which  the  adap- 
tive movements  are  dependent  upon  the  machinery  supplied 
by  nature  to  the  organism  itself.     As  soon  as  the  power  of 
discrimination  has  advanced  far  enough  to  be,  not  only  con- 
sciously precipient,  but  deliberatively  rational,  a  wholly  new 
state  of  things  is  inaugurated.    For  now  the  organism  is  no 
longer  dependent  for  its  adjustments  upon  the  immediate 
results  of  its  own  co-ordinated  movements.    From  the  time 
that  a  stone  was  first  used  by  a  monkey  to  crack  a  nut,  by  a 
bird  to  break  a  shell,  or  even  by  a  spider  to  balance  its  web, 
the  necessary  connexion  between  the  advance  of  mental  dis- 
crimination and  muscular  co-ordination  was  severed.     With 
the  use  of  tools  there  was  given  lo  Mind  the  means  of  pro- 
gressing independently  of  further  progress  in  muscular  co- 
ordination.    And  so  marvellously  has  the  highest  animal 
availed  itself  of  such  means,  that  now,  among  the  civilized 
races  of  mankind,  more  than  a  million  per  cent,  of  his  adjus- 
tive  movements  are  performed  by  mechanisms  of  his  own 
construction.     Wonderful  as  are  the  muscular  co-ordinations 
of  a  tight-rope  dancer,  they  are  nothing  in  point  of  utility  as 
compared  with  the  co-ordinated  movements  of  a  spinning- 
jenny.     Therefore,  although  man  owes  a  countless  debt  of 
gratitude  to  the  long  line  of  his  brutal  ancestry  for  bequeath- 
ing to  him  so  surpassingly  exquisite  a  mechanism  as  that  of 
the  human  body— a  mechanism  without  which  it  would  be 
.  impossible  for  him,  with  any  powers  of  mind,  to  construct 
the  artiiicial  mechanisms  which  he  does— still  man  may  justly 
feel  that  his  charter  of  superiority  over  the  lower  animals  is 
before  all  else  secured  by  this,  that  his  powers  of  adjustive 
movement  have   been    emancipated    from   their    necessary 
alliance  with  his  powers  of  muscular  co-ordination. 
_    _  I  say,  from  his  powers  of  muscular  co-ordination,  because 
It  IS  evident  that  our  powers  of  adjustive  movement,  and  so 
of  adaptation  in  general,  have  never  been,  and  can  never  he, 
emancipated  from  a  necessary  alliance  with  our  powers  of 
nervous  co-ordination. 

I  shall  now  sum  up  the  results  of  our  enquiry  so  far 
as  it  has  hitherto  gone.  First,  we  found  the  Criterion  of 
Aliud,  ejectively  considered,  to  consist  in  the  exhibition  of 


ifni 


I! ;  I 


t '■'}'< 


60 


MENTAL  EVOLUTION  IN  ANIMALS. 


Choice,  and  the  evidence  of  Choice  we  found  to  consist  in  the 
■performance  of  adaptive  action  suited  to  meet  circumstances 
which  have  not  been  of  such  frequent  or  invariable  occur- 
rence in  the  life-history  of  the  race,  as  to  have  been  specially 
and  antecedently  provided  for  in  the  individual  by  the  in- 
herited structure  of  its  nervous  system.  The  power  of  learn- 
InfT  by  individual  experience  is  therefore  the  criterion  of 
Mind.  But  it  is  not  an  absolute  or  infallible  criterion ;  all 
tlhat  can  be  said  for  it  is  that  it  is  the  best  criterion  available, 
and  that  it  serves  to  fix  the  upper  limit  of  non-mental  action 
more  precisely  than  it  does  the  lower  limit  of  mental ;  for  it 
is  probable  that  the  power  of  feeling  is  prior  to  that  of  con- 
sciously learning. 

Having  thus  arrived  at  the  best  available  criterion  of 
Mind  considered  as  an  eject,  we  next  proceeded  to  consider 
the  objective  conditions  under  which  known  Mind  is  invari- 
ably found  to  occur.    This  led  us  briefly  to  inspect  the 
structure  and  functions  of  the  nervous  system,  and,  while 
treating  of  the  physiology  of  reflex  action,  we  found  that 
everywhere  the  nervous  machinery  is  so  arranged  that  there 
is  no  alternative  of  action  presented  to  the  nerve-centres 
other  than  that  of  co-ordinating  the  group  of  muscles  over 
the  combined  contractions  of  which  they  severally  preside. 
The  question  therefore  arose — How  are  we  to  explain  the  fact 
that  the  anatomical  plan  of  a  nerve-centre  with  its  attached 
nerves  comes  to  be  that  which  is  needed  thus  to  direct  the 
nervous  stimuli  into  the  channels  required  ?    The  answer  to 
this  question  we  found  to  consist  in  the  property  which  is 
**  shown  by  nervous  tissue  to  grow  by  use  into  the  directions 
which  are  required  for  further  use.     This  subject  is  as  yet 
an  obscure  one— especially  where  the  earliest  stages  of  such 
adaptive  growth  are  concerned— but  in  a  general  way  we  can 
understand  that  hereditary  usage,  combined  with  natural  selec- 
tion, may  have  been  alone  sufficient  to  construct  the  number- 
less reflex  mechanisms  which  occur  in  the  animal  kingdom. 

Passing  from  reflex  action  to  cerebral  action,  we  first 
noticed  that  as  the  cerebral  hemispheres  pretty  closely  re- 
semble in  their  intimate  structure  ganglia  in  general,  there 
can  be  no  reasonable  doubt  that  the  mode  of  their  operation 
-  is  substantially  the  same.  Moreover  we  noted  that,  as  such 
operation  is  here  unquestionably  attended  with  mental  action, 
.  a  strong  presumption  arises  that  the  one  ought  to  coustituta 


THE  EOOT-PRINCIPLES  OF  MIND. 


61 


a  kind  of  obverse  reflection  of  the  other.  Turning,  therefore, 
to  contemplate  this  presumably  obverse  reflection,  we  found 
that  in  many  respects  it  is  most  strikingly  true  that  the 
fundamental  principles  of  mental  operation  correspond  with 
the  fundamental  principles  of  ganglionic  operation.  Thus,  we 
found  that  such  is  the  case  with  memory  and  the  association 
of  ideas  both  of  which  we  found  to  have  their  objective 
counterparts  in  the  powers  of  non-mental  acquisition  which 
are  presented  by  the  lower  ganglia.  For  we  found  that  these 
ganglia  unconsciously  learn  such  exercises  as  they  are  made 
frequently  to  perform,  that  they  forget  their  exercises  if  too 
long  an  interval  is  allowed  to  elapse  between  the  times  of 
practising  them,  but  that  even  when  apparently  quite  for- 
gotten such  exercises  are  more  easily  re-acquired  than 
originally  they  were  acquired.  More  particularly  we  found 
that  the  association  of  ideas  by  contiguity  presents  a  remark- 
ably detailed  resemblance  to  the  association  of  muscular 
movements  by  contiguity.  For,  agreeing  to  take  ideas  as  the 
objective  analogues  of  muscular  movements,  we  observed  when 
we  thus  changed  the  index  of  nervous  operation  from  muscles 
to  ideas,  that  the  strongest  evidence  was  yielded  of  the  method 
of  nervous  evolution  being  everywhere  uniform.  Thus  we 
remarked  that  sensations,  perceptions,  ideas,  and  emotions  all 
more  or  less  resemble  muscular  'co-ordinations  in  that  they 
are  usually  blended  states  of  consciousness,  wherein  each  con- 
stituent part  must  correspond  with  the  activity  of  some 
particular  nervous  element — a  variety  of  such  elements  being 
therefore  concerned  in  the  composite  state  of  consciousness, 
just  as  a  variety  of  such  elements  are  concerned  in  a  com- 
bined movement  of  muscles.  Further,  just  as  the  associa- 
tion of  ideas  is  not  restricted  to  a  blending  of  simultaneous 
ideas  into  one  composite  idea,  but  extends  to  a  linking  of  one 
idea  with  another  in  serial  succession  ;  so  we  saw  that  mus- 
cular movements  exhibit  a  precisely  analogous  tendency  to 
recur  in  the  same  serial  order  as  that  in  which  they  have 
previously  occurred.  Lastly,  we  noted  that  all  the  patholo- 
gical derangements  which  arise  in  the  nerve-centres  that 
preside  over  muscular  activities,  have  their  parallels  in  simi- 
lar derangements  which  arise  in  the  nerve-centres  that  are 
concerned  in  mental  activities. 

Having  thus  dealt  with  the  Physical  Basis  of  Mind,  we 
passed  on  in  the  next  chapter  to  consider  the  Eoot-principles 


62 


MENTAL  EVOLUTION  IN  ANIMALS. 


i 


ir^i. 


^ 


f  n 


:  S 


■  '      i 

,i|      ^ 

of  Mind.  Here  the  object  was  to  trace  the  ultimate  principles 
of  physiology  that  might  be  taken  as  constituting  the  objec- 
tive side  of  those  phenomena  which  on  their  subjective  and 
ejective  sides  we  regard  as  mental.     These  principles  we 
found  to  be  the  power  of  discriminating  between  different 
kinds  of  stimuli  irrespective  of  their  relative  degrees    of 
mechanical  intensity,  coupled  with  the  power  of  performing 
adaptive  movements  suited  to  the  results  of  such  discrimina'^ 
tion.     These  two  powers,  or  faculties,  we  saw  to  occur  in 
•/  germ  even  among  the  protoplasmic  and  unicellular  organisms, 
and  we  saw  that  from  them  upwards  all  organization  may  be 
said  to  consist  in  supplying  the  structures  necessary  to  an 
ever-increasing  development  of  both  these  faculties,  which 
always  advance,   and    must  necessarily   advance,   together. 
Wlien  their  elaboration  has  proceeded  to  a  certain  extentj 
they  begin  gradually  to  become  associated  with  Feeling,  and 
when  they  are  fully  so  associated,  the  terms  Choice  and  Pur- 
pose become  to  them  respectively  appropriate.     Continuing 
,.^  in  their  upward  course  of  evolution,  they  next  become  con° 
/  sciously  deliberative,  and  eventually  rational.     But  although 
when  viewed  from  the  subjective  or  ejective  side  they  thus 
appear,  during  the  upward  course  of  th    ;  development,  to 
become  transformed  from  one  entity  to  another,  such  is  not 
the  case  when  they  are  viewed  from  their  objective  side. 
For,  when  viewed  from  their  objective  side,  the  most  elaborate 
process   of  reasoning,  or  the  most  comprehensive  of  judg- 
ments, is  seen  to  be  nothing  more  than  a  case  of  exceedingly 
refined  discrimination,  by  highly-wrought  nervous  structures, 
between  stimuli  of  an  enormously  complex  character ;   while 
the  most  far-siglited  of  actions,  adapted  to  meet  the  most 
remote  contingencies  of  stimulation,  is  nothing  more  than  a 
neuro-muscular  adjustment  to  the  circumstances  presented  by 
the  environment. 

Thus,  if  we  again  take  mental  operations  as  indices 
whereby  to  study  the  more  refined  working  of  nervous  centres, 
as  we  take  muscular  movements  to  be  so  many  indices' 
"  writ  large,"  of  the  less  refined  working  of  such  centres^ 
we  again  find  forced  upon  us  the  truth  that  the  method  of 
nervous  evolution  has  everywhere  been  uniform;  it  has 
everywhere  consisted  in  a  progressive  development  of  the 
power  of  discriminating  between  stimuli,  combined  with  the 
complementary  power  of  adaptive  response. 


EXPLANATION  OF  THE  DIAGRAM. 


63 


!  J 


ii 

Ms 


CHAPTER  V. 

Explanation  of  the  Diagram. 

We  have  now  sufficiently  considered  the  sundry  first  prin- 
ciples and  prehminary  questions  which  lie  at  the  threshold  of 
our  subject  proper.     It  seemed  to  me  desirable  to  dispose  of 
these  principles  and  questions  before  we  enter  upon  our 
attempt  at  tracing  the  probable  history  of  Mental  Evolution. 
±Jut  now  that  these  first  principles  and  preliminary  questions 
have  been  disposed  of,  so  far  as  their  nature  renders  possible 
the  way  is  as  clear  as  it  can  be  for  us  to  pursue  our  enquirv 
concerning  the  Genesis  of  Mind.     In  order  to  give  definition 
to  the  somewhat  laborious  investigation  on  which  we  are  thus 
about  to  embark,  I  have  thought  it  a  good  plan  to  draw  a 
diagram  or  map  of  the  probable  development  of  Mind  from 
Its  first  beginnings  in  protoplasmic  life  up  to  its  culmination 
m  the  brain  ot  civilized  man.     The  diagram  embodies  the 
results  of  my  analysis   throughout,  and  will  therefore   be 
repeatedly  alluded  to  in  the  course  of  that  analysis— ee 
througaout  the  present  and  also  my  future  work.     I  may 
theretore  begin  by  explaining  the  plan  of  this  diagram. 
^      Ihe  diagram,  as  I  have  just  said,  is  intended  to  represent 
m  one  view  the  whole  course  of  mental  evolution,  supposin^r 
m  accordance  with  our  original  hypothesis,  such  evolution  S 
have  taKen  place.     Being  a  condensed  epitome  of  the  results 
ot  my  analysis   It  is  in  all  its  parts  carefully  drawn  to   a 
scale,  the  ascending  grades  or  levels  of  which  are  everywhere 
determmed  by  the  evidence  which  I  shall  have  to  adduce 
Ihe  diagram  is  therefore  not  so  much  the  product  of  my  indi- 
vidual imagination,  as  it  is  a  summary  of  all  the  facts  whi<li 
science  has  been  able  so  far  to  furnish  upon  the  subject ;  and 
although  It  IS  no  doubt  true  that  the  progress  of  science  may 
attect  the  diagram  to  the  extent  of  altering  some  of  its  details 
I  feel  confident  that  the  general  structur?  of  our  knowledge 
concerning  the  evolution  of  mind  is  now  sufficiently  cohereSt 


!;ir-'i, 


64 


MENTAL  EVOLUTION  IN  ANIMALS. 


h' 


;  V 


to  render  it  highly  improbable  that  this  diagrammatic  repre- 
sentation of  it  will,  in  the  future,  be  altered  in  any  of  its 
main  features  by  any  advances  that  science  may  be  destined 
to  make. 

From  the  groundwork  of  Excitability,  or  the  distinguish- 
ing peculiarity  of  living  matter,  I  represent  the  structure  of 
mind  as  arising  by  a  double  root — Conductility  and  Discrimi- 
nation.    To  what  has  already  been  said  on  these  topics  it  is 
needless  to  add  more.    We  have  seen  that  the'  distinguishing 
property  of  nerve-fibre  is  that  of  transmitting  stimuli  by  a 
propagation  of  molecular  disturbance  irrespective  of  the  pas- 
sage of  a  contraction  wave ;  and  this  property,  laying  as  it 
does  the  basis  for  all  subsequent  co-ordination  of  protoplasmic 
(muscular)  movements,  as  well  as  of  the  physical  aspect  of 
all  mental  operations,  deserves  to  be  marked  off  in  our  map 
as  a  distinct  and  important  principle  of  development ;  it  is 
the  princi|>l3  which  renders  possible  the  executive  faculty  of 
appropriately  responding  to  stimuli.    Not  less  deserving  of 
similar  treatment  is  the  cognate  principle  of  Discrimination, 
which,  as  we  have  seen,  is  destined  to  become  the  most 
important  of  the  functions  subsequently  distinctive  of  nerve- 
cells  and  ganglia.     But  we  have  also  seen  that  both  Conduc- 
tility and  Discrimination  first  appear  as  manifested  by  the 
cellular  tissues   of  plants,  if    not  even  in  some  forms  of 
apparently  undifferentiated  protoplasm.     It  is,  however,  only 
when  these  two  principle^j  are  united  within  the  limits  of  the 
same  structural  elements  that  we  first  obtain  optical  evidence 
of  that  differentiation  of  tissue  which  the  histologist  recognizes 
as  nervous;   therefore  I  have  represented  the  function   of 
nerve-tissue  in  its  widest  sense,  Neurility,  as  formed  by  a 
confluence  of    these  two    root-principles.      Neurility   then 
passes  into  Eeflex  Action  and  Volition,  which  I  have  repre- 
sented as  occupying  the  axis  or  stem  of  the  psychological 
tree.     On  each  side  of  this  tree  I  have  represented  the  out- 
growth of  branches,  and  for  the  sake  of  distinctness  I  have 
confined  the  branches  which  stand  for  the  faculties  of  Intellect 
on  one  side,  while  placing  those  which  represent  the  Emotions 
upon  the  other.     The  level  to  which  any  branch  attains  re- 
presents the  degree  of  elaboration  which  the  faculty  named 
thereon  presents;  so  that,   for  instance,   when  the  branch 
Sensation,  talcing  origin  from  Neurility,  proceeds  to  a  certain 
level  of  development,  it  gives  off  the  cuiiiiiioucement  of  Per- 


EXPLANATION  OF  THE  DIAGRAIL 


65 


ception,  and  then  continues  in  its  own  line  of  development  to 
a  somewhat  higher  level.     Similarly,  Imagination  arises  out 
of  Perception,  and  so  with  all  the  other  branches.     Thus  the 
fifty  levels  which  are  drawn  across  the  diagram  are  intended 
to  represent  degrees  of  elaboration ;  tliey  are  not  intended  to 
represent  intervals  of  time.     Such  being  the  case,  the  various 
products  of  mental  evolution  are  placed  in  parallel  columns 
upon  these  various  levels,  so  as  to  exhibit  the  comparative 
degrees   of   elaboration,  or  evolution,  which  thev  severally 
present.     One  of  these  columns  is  devoted  to  the  psycho- 
logical scale  of  intellectual  faculties,  and   another  to  the 
psychological  scale  of  the  emotional.     But  for  the  danger  of 
rendering  the  diagram   confused,  these  faculties  might"  have 
been  represented  as  secondary  branches  of  the  psycholooical 
tree  ;  in  a  model  this  might  well  be  done,  but  in  a  diagram  it 
would  not  be  practicable,  and  therefore  I  have  restricFed  the 
branching  structure  to  represent  only  the  most  generic  or 
tiindamental  ot  the  psychological  faculties,  and  relegated  those 
ot  more  specific  or  secondary  value  to  the  parallel  columns  on 
either  side  of  the  branching  structure.    In  these  two  columns 
1    have   throughout   written   the   name   of    the   faculty   at 
what  I  conceive  to  be  the  earliest  stage,  or  lowest  level  of  its 
elaboration  ;  i.e.,  where  it  first  gives  evidence  of  its  existence 
m  another  parallel  column  I  have  given  the  grades  of  mental 
evolution  which  I  take  to  be  characteristic  of  sundry  crroups 
m  the  animal  kingdom,  and  in  yet  another  column  I  have 
represented  the  grades  of  mental  evolution  which  I  take  to 
be  characteristic  of  different  ages  in  the  life  of  an  infant 

In  my  subsequent  work  I  shall  fill  up  all  the  levels  in  . 
these  vertica.  columns  which  are  now  left  blank,  on  account  ' 
ot  the  text  of  the  present  work  being  restricted  to  the  mental 
evolution  of  animals.  At  first  I  intended  in  this  work  to 
truncate  the  whole  diagram  at  the  level  where  mental  evolu- 
tion in  animals  ends— ie.,  at  the  level  marked  28— and  to 
reserve  the  continuation  of  the  stem  and  branches,  as  well  as 
tnat  ot  the  parallel  columns,  for  my  ensuing  work.  But 
a  terwards  I  thought  it  was  better  to  supply  the  continuation 
ot  the  stem  and  branches,  in  order  to  show  the  proportion 
which  I  conceive  to  obtain  between  the  elaboration  of  the 
higher  faculties  as  they  occur  in  animals  and  the  same 
taculties  as  they  occur  in  man. 

Confining,  then,  our  attention  to  the  first  twenty-eight 


m 
11 


PI 


li!!    i' 


ii;  ■ 


! 


_jijaami  ' 


11 


I 


66 


MENTAL  EVOLUTION  IN  ANIMAL3. 


^levels  with  which  alone  the  present  essay  is  to  be  concerned,  if 
we  pitch  upon  any  one  of  them  at  random,  we  shall  obtain  a 
certain  rough  estimate  of  the  grade  of  mental  evolution  which 
IS  presented  by  the  animals  named  upon  that  level. 
_      To  avoid  misapprehension  I  may  add  that  in  thus  render- 
ing a  diagrammatic  representation  of  the  probable  course  of 
mental  evolution  with    the    comparisons   of   psycholo<ncal 
development  exhibited  in  the  parallel  columns,  I   do   not 
suppose  that  the  representation   is  more  than  a  rou"h  or 
general  outline   of   the   facts;    and,   indeed,   I    have  "only 
resorted  to  the  expedient  of  thus  representing  tlie  latter  for 
the  sake  of  convenience  in  my  subsequent  discussion,   llow^h. 
as  this  outline  of  historical  psycholos^^y  may  be,  it  will  serve 
Its  purpose  if  it  tends  to  facilitate  the  exposition  of  evidence 
and  afterwards  serves  as  a  dictionary  of  raference  to  the  more 
important  of  the  facts  which  I  hope  this  evidence  will  be  able 
to  substantiate. 

Such  being  the  general  use  to  which  I  intend  to  put  the 
diagram,  I  may  here  most  fitly  make  this  general  remark  in 
regard  to  it.     In  the  case  alike  of  the  stem,  branches,  and  the 
two  parallel  columns  on  either  side— i.e.,  all  the  parts  of  the 
diagram  which  serve  to  denote  psychological  faculties— we 
must  remember  that  they  are  diagrammatic  rather  than  truly 
representative.     For  in  nature  it  is  as  a  matter  of  fact  impos- 
sible to  determine  any  hard  and  fast  lines  between  the  com- 
pleted development  of  one  faculty  and  the  first  origin  of  the 
next  succeeding  faculty.     The  passage  from  one  faculty  to 
another  is  throughout  of  that  gradual  kind  wliic]    is  charac- 
teristic of  evolution  in  general,  and  which,  while  never  pre- 
venting an  eventual  distinction  of  species,  always  renders  it 
impossible  to  draw  a  line  and  say— Here  species  A  ends  and 
species  B  begins.     Moreover,  I  cannot  too  emphatically  im- 
press my  conviction  that  ar.;  psychological  classification  of 
taculties,  however  serviceable  it  may   be   for  purposes  of 
analysis  and  discussion,  must  necessarily  be  artificial.     It 
would,  in  my  opinion,  be  a  most  erroneous  view  to  take  of 
Mmd  to  regard  it  as  really  made  up  of  a  certain  numl^er  of 
distinct  faculties— as  erroneous,  for  example,  as  it  would  be 
to  regard  the  body  as  made  up  of  the  faculties  of  nutrition 
excitability,  generation,  and  so  on.     All  such  distinctions  are 
usetul  only  for  the  purposes  of  analysis ;  they  are  abstractions 
ot    our  own  making  for  our    own  convenience,  and    not 


t  I-  h 


not 


EXPLANATION  OP  THE  DIAOEAM. 


67 


naturally  distinct    parts  of    the   structure   which  we    are 


exainininf];. 


But  although  it  is  desirable  to  keep  these  caveats  in  our 
memory,  I  do  not  think  that  either  the  artificial  nature  of 
psychological  classification  or  the  fact  that  we  have  to  do 
with  a  gradual  process  of  evolution,  constitutes  any  serioua 
vitiation  of  the  mode  of  representation  which  I  have  adopted. 
For,  on  the  one  hand,  some  classification  of  faculties  we  must 
have  for  the  purposes  of  our  inquiry  ;  and,  on  the  other  hand, 
I  have  as  much  as  possible  allowed  for  tlie  unavoidable  defect 
in   the   representation   which   arises   from   evolution    being 
gradual,  by  making  the  branches  of  the  arborescent  structure 
wide  at  their  bases,  and  by  allowing  each  of  them,  after  giving 
off  the  next  succeeding  branch,  to  continue  on  its  own  course  of 
development ;  so  that  both  the  parent  and  daughter  faculty- 
are  represented  as  occupying  for  a  more  or  less  considerable 
distance  the  same  levels  of  development — in  each  case  my 
estimate  of  the  comparative  elaboration  which  the  completed 
faculty  betokens  being  represented  by  the  vertical  height  of 
its  apex.     Besides,  as  already  stated,  faculties  named  in  the 
two  parallel  columns  are  written  upon  tliose  levels  where  I 
have  either  a  priori  reasons  or  actual  evidence  to  conclude 
that  they  first  definitely  appear  in  the  growing  structure  of 
Mind;  in  this  way  the  difficult  question   of  assigning  the 
lower  limit   of  evolution   at  which  any  particular   facully 
begins  to  dawn  is  as  much  as  possible  avoided. 

It  is  almost  needless  to  add  that  in  preparing  this  diagram 
I  have  resorted  to  speculation  in  as  small  a  measure  as  the 
nature  of  the  subject  permits.  Nevertheless  it  is  obvious 
that  the  nature  of  the  subject  is  such  that,  in  order  to  com- 
plete the  diagram  in  some  of  its  parts,  I  have  been  obliged  to 
resort  to  speculation  pretty  largely.  I  think,  however,  that 
as  the  exposition  proceeds,  it  will  be  seen  that,  if  the  funda- 
mental hypothesis  of  mental  evolution  having  taken  place  is 
granted,  my  reasoning  as  to  the  probable  history  of  the  pro- 
cess does  not  anywhere  involve  speculation  of  an  extravagant 
or  dangerous  kind.  In  matters  of  detail— such,  for  instance, 
as  the  comparative  elevation  of  the  different  branches  in  the 
psychological  tree — my  estimates  may,  probably  enough,  be 
more  or  less  erroneous  ;  but  the  main  facts  as  to  the  sequence 
of  the  faculties  in  the  order  of  their  comparative  degrees  of 
elaboration  are  mere  corollaries  from  our  fundamental  hypo- 


141 


!r  ii 


■  11 


'ifii 


ill  : 


i 


f'l 


i  ,    ■  I! 


63 


MENTAL  EVOLUTION  IN  ANIMALS. 


theses ;  and,  as  we  shall  see.  these  facts,  as  I  have  presented 
them,  are  su-  Mud  or  corroborated  by  many  others  drawn 
A^^n  '''.r  '  '?  "  ^'^?  psychology  of  animals  and  children. 
;fg*\"'^**thec(,himus  devoted  to  the  emotions  and  faculties 
ot  intelloct,  the  results  of  actual  observation  predominate  over 
those  yie  ded  by  speculation ;  while  in  the  remaining  columns 
the^results  tabulated  are  for  the  most  part  due  to  observa- 

Therefore   I  submit  tl.at  if  tJ-e  hypothesis   of  mental 
evolution  be  granted,  and  if  all  the  matters  of  observable 
lact  which  the  diagram  serves  to  express  are  eliminated,  com- 
paratively  little  in  the  way  of  deductive  reasoning  is  left : 
and  of  this  ittle  most  follows  as  necessary  consequence  from 
the  original  hypothesis  of  mental  evolution  having  taken 
place.     Of  coiirse  any  one  who  does  not  already  accept  the 
theory  of  evolution  in  its  entirety,  may  object  that  I  am 
thus  escaping  from  the  charge  of  speculation  only  by  assum- 
ing the  truth  of  that  which  grants  me  all  tliat  I  require     To 
this  I  answer  that  as  far  as  the  evidence  of  Mental  Evolution 
considered  as  a  fact  is  open  to  the  charge  of  being  specula:^ 
tive,  I  must  leave  the  ol^ector  to  lodge  hif  objection  against 
Mr  Darwin's  "Origin  of  Species  "  and  " Descent  of  Man."    I 
shall  be  abundantly  satisfied  with  my  own  work  if,  takincr 
the  process  of  Mental  Evolution  as  conceded,  I  can  make  it 
clear  that  the  mam  outlines  of  its  history  mav  be  determined 
without  any    considerable  amount  of  speculation,   as  dis- 
tinguished from  deduction  following  by  way  of  necessary 
consequence  from  the  original  hypothesis. 

Having  thus  explained  the  plan  and  principles  of  the 
diagram,  I  shall  now  consider  the  levels  from  the  lowest  as 
far  as  the  rise  of  the  first  branch,  i.e.,  from  1  to  14.  After 
what  has  already  been  said  in  the  foregoing  chapters  on  the 
Ihysical  Basis  and  Root-principles  of  Mind,  our  consideration 
ot  this  part  of  the  diagram  need  not  detain  us  lonrr. 

Levels  1  to  4  are  occupied  by  Excitability,  Protoplasmic 
Movements  Protoplasmic  Organisms,  and  the  generative 
elements  which  have  not  yet  united  to  start  the  Embryo  of 
Man.  From  4  to  9  we  have  the  levels  filled  by  the  rise  and 
progress  of  the  functions  Conductility  and  Discrimination, 
which  by  their  subsequent  union  at  9  lay  the  basis  of 
Neurility.or  the  stem  of  Mind;  in  these  levels  occur  the 


EXPLANATION  OP  THE  DIAGBAM, 


69 


■ 


Non-nervous  Adjustments,  Unicellular  Organisms,  ana  part  of 
the  Life-history  of  the  Embryo.  Between  9  and  14  is  repre- 
sented the  development  of  Neurility  and  its  passage  into 
Eetlex  Action ;  the  parallel  columns  within  this  sj)ace  are 
therefore  respectively  filled  with  Partly-nervous  Adjustments 
and  the  beginning  of  True  Nervous  Adjustments,  Unknown 
Animals,  probably  Ccelenterata,  perhaps  extinct,  and  another 
portion  of  the  Life-history  of  the  Embryo.  I  here  speak  of 
"unknown  animals"  because,  so  far  as  investigation  has 
hitherto  gone,  the  animals  in  which  nerve-tissue  Hrst  began 
t<  •  be  differentiated  have  not  yet  been  found.  In  the  lowest 
animals  where  this  tissue  has  been  found — the  Medusa' — it 
appears  as  already  well  differentiated.  The  ganglion  cells, 
however,  show  in  a  most  unmistakeable  manner  their  parent- 
age from  epitlielium — their  structure,  in  fact,  often  resembling 
that  of  modified  epithelium  more  than  that  of  true  nerve- 
cells.*  In  these  structures,  therefore  (as  in  the  analogous 
histological  elements  met  with  in  the  embryonic  nerve-tissue 
of  higher  animals),  we  have  a  link  which  connects  true  nerve- 
tissue  with  its  cellular  ancestry,  and  thus  it  is  comparatively 
immaterial  whether  or  not  the  animals  which  presented  the 
earlier  stages  of  this  histological  transition  are  still  in  exist- 
ence. Thus  we  need  not  wait  to  discuss  Kleinenberg's  view 
on  the  "  neuro-muscular  "  cells  of  Hydra. 

*  See  Prof.  E.  A.  Schafer  on  Nervous  System  of  Aurella  Aurita,  Phil. 
Trans.,  1878,  and  Profs.  O.  aud  fi.  Hertwig  oa  Dat  Nervensystem  tirul  die 
Shinesorpane  der  Medusen. 


I' 


I  3 

I!  ''■ 


'-{ 


70 


MENTAL  EVOLUTION  IN  ANTTJAIQ. 


w 


\ . 


CHAPTER  VI. 

Consciousness. 

Hitherto  in  this  work  I  have  been  considering,  as  exclu- 
sively as  the  nature  of  the  subject  permits,  the  physical  or 
objective  aspect  of  mental  processes,  and  of  the  antecedents 
of  these  processes  in   the  non-mental  activities  of  living 
organisms.     It  now  devolves  upon  us  to  turn  to  the  sub*^ 
jective  side  of  tlie  matter,  and  still   more  closely,  I  may 
observe,  to  the  ejective  side  of  it.     That  is  to  say,  from  this 
point  onward  my  endeavour  will  be  to  trace  the  probable 
course  of  Mental  Evolution  by  having  regard  to  truly  mental 
phenomena,  so  far  as  these  admit  of  analysis  by  subjective 
or  ejective  methods.     I  desire,  therefore,  to  draw  prominent 
attention  to  the  fact  that  from  this  point  in  my  treatise  I 
take,  as  it  were,  a  new  departure;  for  if  this  is  not  kept  in 
mind,  my  exposition  may  appear  to  resemble  two  separate 
essays  bound  together  rather  than  one  continuous  whole.     In 
my  endeavour  to  draw  a  sharp  line  of  demarcation  between 
the  physiology  and  the  psychology  of  my  subject,  I  have 
found  it  impossible  to  discuss   the  one  without  numerous 
allusions  to  the  other — the  consequence  being  that  hitherto, 
■while  treating  as  exclusively  as  I  could  of  the  physiology  of 
vital  processes,  I  have  been  obliged  frequently  to  refer  to  the  " 
psychology  of  mental  processes,  a  knowledge  concerning  the 
main  facts  of  which  I  have  taken  for  granted  on  the  part  of 
any  one  who  is  likely  to  read  this  book.     Thus  it  happens 
that  in  now^  turning  to  investigate  the  psychology  of  these 
proce>.ses,  it  is  impossible  to  avoid  a  certain  amount  of  over- 
lapping with  what  has  gone  before.     For  example,  in  my 
chapter  on  the  Physical  Basis  of  Mind,  it  was  clearly  impos- 
sible not  to  allude  to  such  leading  principles  of  psychology 
as  sensation,  perception,  ideation,  and  others.     Therefore,  in 
now  undertaking  an  investigation  of  these  various  principles 


CONSCIOUSNESS. 


71 


in  the  order  of  their  probable  evohition,  it  may  ofton  appear 
that  I  am,  as  it  were,  going  back  upon,  or  in  part  repeating, 
what  I  have  ahvady  said.  But  this  apparent  defect  in  the 
method  of  my  exposition  will,  I  think,  be  seen  on  closer 
attention  to  be  more  than  compensated  for  by  the  advantage 
of  avoiding  confusion  between  physiology  and  psychology. 
It  would,  lor  instance,  have  been  easy  to  have  split  up  tlie 
chapter  on  the  Physical  Basis  of  Mind  already  alluded  to, 
and  to  have  apportioned  its  various  parts  to  those  among  the 
succeeding  chapters  which  treat  of  the  psychological  aspects 
of  the  pliysiological  princii)les  set  forth  in  those  various 
parts;  but  the  result  would  have  been  largely  to  have 
obscured  th(3  doctrine  which  I  desired  to  make  plain  through- 
out— viz.,  that  all  mental  processes  must  be  regarded  as  pre- 
senting physical  counterparts.* 

So  much  in  explanation  of  my  method  being  understood, 
I  shall  begin  the  psychology  of  mental  evolution  by  con- 
sidering that  in  which  the  mind-element  must  be  regarded  as 
consisting — namely.  Consciousness.  Turning  to  the  diagram, 
it  wilt  be  observed  that  I  have  written  the  word  "  Con- 
sciousness "  in  a  perpendicular  direction,  beginning  at  level  14 
and  extending  to  level  19.  My  reason  for  doing  this  is 
because  the  rise  of  Consciousness  is  probably  so  gradual,  and 
certainly  so  undefined  to  observation,  that  any  attempt  to 
draw  the  line  at  which  it  does  arise  would  be  impossible, 
even  on  the  rough  and  general  scale  wherewith  I  havp  endea- 
voured to  draw  the  lines  at  which  the  sundry  mental  faculties 
may  be  regarded  as  taking  origin.  Therefore  I  have  repre- 
sented the  rise  of  Consciousness  as  occupying  a  considerable 
area  in  our  representative  map,  instead  of  a  definite  line. 
This  area  I  make  to  begin  with  the  first  development  of 
"  Nervous  Adjustments,"  and  to  terminate  with  the  earliest 
appearance  of  the  power  of  associating  ideas. 

In  now  proceeding  to  justify  this  assignment  of  limits 
between  the  earliest  dawn  of  Consciousness  and  the  place 
where  Consciousness  may  first  be  regarded  as  truly  such,  I 
may  best  begin  by  saying  that  I  shall  not  attempt  to  define 

•  It  seems  almost  needless  to  add  that  the  impossibility  of  entirely  Bopa- 
raling  psychology  from  physiology  for  the  purposes  of  exposition  will,  mutatis 
mutandis,  confinue  to  meet  us  more  or  less  throughout  the  following,  as  it 
has  throughout  the  preceding  chapters ;  but  I  sliall  endeavour  always  to 
make  it  clear  when  I  am  speaking  of  mental  processes  and  when  of  physical. 


i. 


M 


Jtf^i^^ 


m 


i,i 


:  'ill 


72 


MENTAL  EVOLUTION  IN  ANIMALS 


What  is  meant  by  Consciousness.    For,  like  the  word  "  Wnd  " 
any  defiSn      Tf  ..      ^^'\^^'^>  cannot  be  comprehended  in 

that  of  an  ahnost  unrecognizable  affection    ,,nS,tl't   "J 

rZeirZT''"'r-  ^"^  S^dual,  that  ev  n  wWnn    L 
oi  of  objective  analysis,  to  correspond;  and  this  weTflSd.' 


i  il! 


CONSCIOUSNESS. 


73 


For  in  our  own  organisms  we  know  that  reflex  actions  are 
not  accompanied  by  consciousness,  altliougli  the  complexity 
of  the  neuro-muscular  systems  concerned  in  these  actions 
may  be  very  considerable.  Clearly,  therefore,  it  is  not  mere 
complexity  of  ganglionic  action  that  determines  conscious- 
ness. What,  then,  is  the  difference  between  the  mode  of 
operation  of  the  cerebral  hemispheres  and  that  of  the  lower 
ganglia,  which  may  be  taken  to  correspond  with  the  great 
suijjective  distinction  between  the  consciousness  which  may 
attend  the  former  and  the  no-consciousness  which  is  inva- 
riably characteristic  of  the  latter  ?  I  think  the  only  difference 
that  can  be  pointed  to  is  a  difference  of  rate  or  time.  We 
know  by  actual  measurement,  as  we  shall  subsequently  see 
in  more  detail,  that  the  cerebral  hemispheres  work  more 
slowly  while  undergoing  those  changes  which  are  accom- 
panied by  consciousness  than  is  the  case  with  the  activities 
of  the  lower  centres.  In  otlier  words,  tlie  period  between  the 
fall  of  a  stimulus  and  the  occurrence  of  responsive  movement 
is  notably  longer  if  the  stimulus  has  first  to  be  perceived,  than 
it  is  if  no  perception  is  required.  And  this  is  proved,  not 
only  by  comparing  the  latent  period  (or  the  time  which 
elapses  between  t!  ■.  stimulation  and  the  response)  in  the  case 
of  an  action  involvxng  one  of  the  lower  centres  and  that  of  an 
action  involving  the  cerebral  hemispheres  in  perception ;  but 
also  by  comparing  the  latent  period  in  the  case  of  one  and 
the  same  cerebral  action  which  from  having  originally  involved 
perception  has  through  repetition  become  automatic.  An  old 
sportsman  will  have  his  gun  to  the  shoulder,  by  an  almost 
unconscious  act,  the  moment  thit  a  bird  unexpectedly  rises; 
a  novice  similarly  surprised  wii,  spend  a  valuable  second  in 
"taking  in"  the  situation.  And  any  number  of  similar  facts 
might  be  given  to  show  that  if  few  things  are  "  as  quick  as 
thought,"  reflex  or  automatic  action  is  one  that  is  quicker. 
Further,  in  a  general  v/ay  it  can  be  shown  that  the  more 
elaborate  a  state  of  consciousness  is,  the  more  time  is  required 
for  its  elaboration,  as  we  shall  see  more  in  detail  when  we 
come  to  treat  of  Perception. 

Now  what  does  this  greater  consumption  of  time  imply  ? 
It  clearly  implies  that  the  nervous  mechanism  concerned  has 
not  been  fully  habituated  to  the  performance  of  the  response 
required,  and  therefore  tliat  instead  of  the  stimulus  merely 
needing  to  touch  the  trigger  of  a  ready- formed  apparatus  of 


!-,ii 


1V 


m 


74 


rii 


m 


MESTAL  ETOLOTIOS  lU  AOTMA13. 


response  is  jJddS     JP'^f".^'™"'' before  the  appropriate 

this  ph.y  o/Suli  iJ"t  'e  Sence'  o?'"  J-'^,"""!" ».-  "^ 
stances"  is  known  a«in,l,:„-'^L         "  "difficult  circmn- 

conscious^ess-rch  4  t?r^^^  '"'  ,?™"  "  »  »»»Pl«  "«*  ot 
time  is  reqnived  by  tto  erebrlS"'  J  "  P?'-«q«ion-more 
appropriate  responseto  a  non  haH  Z  "•  '"PP'^^S  an 

required  by  tlie  lower  np,t„  ^  "'  experience,  than  is 

complicated  of  rX  ac  to^T'  ^r  performing  the  most 
habitual  exper fence  I^,  ,„  ?  !7  ™^  f  '"'P""""  to  thdr 
discharge  Cittn  wl  ''^.i^^Vui'tZf/  ""™"' 

And  this  c„,n  1  X„f  f»«s  wh  ch  f  7''''?'  'f'"'-^*--- 
expression  in  a  len'-tl  enh,  "  .f  t'b.  "','  '"  l'''.)'«i»l''Hi-al 
a  psyehoh,gic„l  e.^:^:\^l^  t^^i^''  -° 

deaH:^^;;;fr.';f::hfch''':,s,f:':;]iT''^T'^^^'^^ 

parative  sense  siinnlp  nrp  ,?,'''"-''  possibly  and  m  a  com- 
sciousness.  Or,  in  th^  3s "f  a17 ^  plienomena  of  con- 
And  th3  quid  fuccession  oT^i::^'^  •  "'*^''-^'  T^^^  '^'''^''- 

*  Principles  of  Ps,/choloq,/,  vol  i  n  Aq^;  t  m  •  1  i 
Spencer  is  not  sw/Iioientlv  evnlie  fc  o  H  .'..Fi-n  .1  f  '"^'  ^'o^o^^'-  t'lat  Mr. 
where,  in  showing  that  '  t^^mS^^'lI^^J^'"'  quoted  passage  or  else- 
constituted  bj  the  mere  c^m^rrZof  .r.nii;""'"""'' '"'*  V' "^^^  "«'^^s^'i'-ily 
said,  sucli  complexity  in  i.self  doe  It  ,.nn  f! .  1'  '''^'^"- ,  ^'"^'^'"^'  ««  ^  '>'^ve 
rise  of  consciousness!  except  n  so  for  \sknav"h'  ""^"""«  '°  ^''^  ^''^'^  »''« 
tera.  the  ganghoaic  fri^tioi.  wMchTa  txireS  brai^;X^^^^^^^^^^^^  ^^  "^^^ 


CONSCIOUSNESS. 


75 


them  into  more  and  more  complex  and  varied  relations  with 
their  environment),  the  primitive  assignment  of  a  special 
nervous  mechanism  to  meet  the  exigencies  of  this  or  that 
special  group  of  stimuli  becomes  no  longer  practicable,  and 
the  higher  nerve-centres  have  therefore  to  take  on  the  func- 
tion of  focussing  many  and  more  or  less  varied  stimuli,  in 
order  to  attain  to  that  higher  aptitude  of  discrimination  in 
which  we  have  already  seen  to  consist  tlie  distinctive  attri- 
bute of  Mind.     And,  as  Mr.  Spencer  has  observed,  "  the  co- 
ordination of  many  stimuli  into  one  stimulus  is,  so  far  as  it 
goes,  a  reduction  of  difi'used  simultaneous  changes  into  con- 
centrated serial  changes.     Whether  the  combined  nervous 
acts  which  take  place  when  the  fly-catcher  seizes  an  insect 
are  reg-arded  as  a  series  passing  through  its  centre  of  co- 
ordination in  rapid  succession,  or  as  consolidated  into  two 
successive  states  of  its  centre  of  co-ordination,  it  is  equally 
clear  that  the  changes  going  on  in  its  centre  of  co-ordination 
have  a  much  more  decided  linear  arrangement  than  have  the 
cliangcs  going  on  in  the  scattered  ganglia  of  a  centipede." 
And  this  linear  character  of  the  change  is,  of  course,  one  of 
the  most  distinctive  features  of  consciousness  as  known  to 
ourselves  subjectively. 

It  will  have  been  ol)served  that  this  interpretation  of  the 
rise  of  consciousness   is  purely  empiiical.      We   know   by 
immediate   or   subjective   analysis   that   consciousness   only 
occurs  when  a  nerve-centre  is  engaged  in  such  a  focussing 
of  varied  or  comparatively  unusual  stimuli   as  have  been 
described,  and  when  as  a  preliminary  to  this  focussing  or  act 
of  discriminative  adjustment  there  arises  in  the  nerve-centre 
a  comparative  turmoil  of  stimuli  coursing  in  more  or  less 
unaccustomed  directions,  and  therefore  giving  rise  to  a  com- 
parative delay  in  the  occurrence  of  the  eventual  response. 
But  we  are  totally  in  the  dark  as  to  the  causal  connection,  if 
any,  between  such  a  state  of  turmoil  in  a  ganglion  and  the 
occurrence  of  consciousness.     Whetlier  it  is  tlie  Angel  that 
descends  to  trouble  the  waters,  or  the  troubling  of  the  waters 
that  calls  down  the  Angel,  is  really  the  question  which  divides 
the  Spiritualists  from  the  Materialists ;  but  with  this  question 
we  have  nothing  to  do.     It  is  enough  for  all  the  objects  of 
the  present  work  that  we  never  get  the  Angel  without  the 
troubling,  nor  the  troubling  without  the  Angel ;  we  have  an 
empirical  association  between  the  two  which  is  as  valid  for 


(   'i 


■■  1^ 


MM 


!       :l 


- 


Ill 


76 


KENTAL  EVOLUTION  IN  ANIMALS. 


the  purposes  of  merely  historical  psychology  as  would  be  a 
full  understanding  of  the  causal  connection,  if  there  is  any 
such  connection  to  be  understood. 

So  much,  then,  for  the  physical  conditions  under  which 
consciousness  is  always  and  only  found  to  occur.  It  remains 
briefly  to  conclude  this  chapter  by  showing  that  these  con- 
ditions may  most  reasonably  he  regarded  as  first  arising 
within  the  limits  between  which  I  have  represented  the 
origin  of  consciousness. 

Eememberiug  what  has  already  been  said  concerning  the 
gradual  or  undefined  manner  in  which  consciousness  probably 
dawned  upon  the  scene  of  life,  and  that  I  therefore  represent 
its  rise  as  occupying  a  wide  area  on  the  diagram  instead  of  a 
definite  line,  I  think  it  least  objectionable  to  place  the  begin- 
ning of  this  dawn  in  nervous  adjustments  or  reflex  action, 
and  the  end  of  it  in  the  association  of  ideas.     For,  on  the  one 
hand,  it  is  clear  from  what  has  been  said  tliat  it  is  impossible 
to  draw  any  definite  line  between  reflex  and  conscious  action, 
inasmuch  as,  considered  objectively  or  as  action,  the  latter 
differs  from  the  former,  not  in  kind,  but  only  in  a  gradual 
advance  in  the  degree  of  central  co-ordination  of  stimuli. 
Therefore,   where  such  central  co-ordination   is    first  well 
established,  as  it  is  in  the  mechanism  of  the  simplest  reflex 
act,  there  I  think  we  may  with  least  impropriety  mark  the 
advent  of  consciousness.     On  the  other  hand,  where  vague 
memory  of  past  experiences  first  passes  into  a  power  of  asso- 
ciating simple  ideas,  or  of    remembering  the   connections 
between  memories,  there  I  think   consciousness   may  most 
properly  be  held  to  have  advanced  sufficiently  far  to  admit  of 
our  regarding  it  as  fairly  begun. 

In  this  scheme,  therefore— which  of  course  it  is  needless 
to  say  I  present  as  a  somewhat  arbitrary  estimate  where  no 
more  precise  estimate  is  possible— the  Coelenterata  are  repre- 
sented as  having  what  Mi.  Spencer  calls  "  the  raw  material 
of  consciousness,"  the  Echinodermata  as  having  such  an 
amount  of  consciousness  as  I  think  we  ma-  voasonably  slip- 
pose  that  they  possess,  if  we  consider  how  multifarious  and 
complicated  their  reflex  actions  have  become,  and  if  we 
reuie)nber  that  in  their  spontaneous  movements  the  neuro- 
muscular adjustments  which  they  exhibit  almost  present  the 
appearance  of  being  due  to  intelligence.*  The  Annelida  I 
•  See  F/iU.  Trans.,  Croonian  Lecture,  1881. 


I  :; 


''H 


CONSCIOUSNESS. 


17 


the 


place  upon  a  still  higher  level  of  consciousness,  because,  both 
Irom  the  facts  mentioned  in  "  Animal  Intelligence"'  and  from 
those  published  by  Mr.  Darwin,*  it  seems  certain  that  their 
actions  so  closely  border  on  the  intelligent  that  it  is  difficult 
to  determine  whetlier  or  not  they  should  be  classed  as  intel- 
ligent. Upon  this  level,  also,  I  represent  the  period  of  the 
embryonic  life  of  Man  as  coming  to  a  close ;  for  although  the 
new-born  chi'd,  from  the  immaturity  of  its  experience,  dis- 
plays no  adjustments  that  can  be  taken  as  indicative  of 
intelligence,  still,  as  its  nerve-centres  arc  so  elaborate  (embo- 
dying the  results  of  a  great  mass  of  hereditary  experience, 
which  although  more  latent  in  the  new-born  child  than  in  the 
new-born  of  many  other  mammals  and  all  birds,  must  still, 
we  should  infer  from  analogy,  count  of  something),  that  we 
can  scarcely  doubt  the  presence  of  at  least  as  much  conscious- 
ness as  occurs  among  the  annelids.  Moreover,  pain  appears 
to  be  felt  bv  a  new-born  child,  inasmuch  as  it  cries  if  injured ; 
and  althougli  this  action  may  be  largely  or  chiefly  reflex,,  we 
may  from  analogy  infer  that  it  is  also  in  part  due  to  feeling. 
The  remaining  levels  occupied  by  the  dawn  of  consciousness 
may  be  considered  as  assigned  to  the  lower  Mollusca — an 
assignment  which  I  think  will  be  seen  to  be  justified  by  con- 
sulting tlie  evidence  given  in  my  former  work  ^i  actions 
performed  by  these  animals  of  a  nature  which  is  unques- 
tionably intelligent. 

•  See  bis  work  on  Earthworms,  ISSl. 


hi    ,;' 

;  n  r 


3 


78 


MENTAL  EVOLUTION  IN  ANIMAL3. 


CHAPTER  YIl 


Mk  f. 


(I 


\  ■  < 


Sensation. 
exclusive  of  the  cnvpMUr  ^^fi  ""'Z  ^^^^P'^ion- ,  -linis,  too,  it  is 

felt   (Reflex  ActTonH'''^'T  adjustments  whic!i  are  un- 


¥  i 


SENSATION. 


79 


faculties ;  it  only  has  to  do  with  the  question  wliether  such 
and  such  a  faculty  occurs  in  such  and  such  an  organism. 
Therefore,  so  long  as  the  question  is  one   of  classifying 
psychical  faculties,  we  can  only  say  that  wherever  there  is 
Feeling  there  is  Sensation,  and  wherever  there  is  no  Feeling 
there  is  no  Sensation.*     But  where  the  question  is  one  of 
classifying  organisms  with  reference  to  their  psychical  facul- 
ties, it  is  clear  that  the  difficulty  of  determining  whether  or 
not  this  and  that  particular  low  form  of  life  has  the  begin- 
nings of  Sensation,  is  one  and  the  same   as  the  question 
whether  it  has  the  beginnings  of  Consciousness.     Now  we 
have  already  considered  this  question,  and  we  have  found  it 
impossible  to  answer;  we  cannot  say  within  broad  limits 
where  in  the  animal  kingdom  consciousness  may  first  be  re- 
garded as  present.     But  for  the  sake  of  drawing  the  line 
somewhere  with  reference  to  Sensation,  I  draw  it  at  the  place 
in  the  zoological  scale  where  we  first  meet  with  organs  of 
special  sense,  that  is  to  say,  at  the  Coelenterata.     In  doing 
this,  it  is  needless  to  observe,  I  am  drawing  the  line  quite 
arbitrarily.     On  the  one  hand,  for  anything  that  is  known  to 
the  contrary,  not  only  the  sensitive  plant  which  responds  to 
a  mechanical  stimulus,  but  even  the  protopl;  ,mic  organisms 
which  respond  to  a  luminous  stimulus  by  congregating  in  or 
avoiding  the  light,  may,  wliile  executing  their  responses,  be 
dimly  conscious  of  feeling ;  and,  on  the  other  hand,  the  mere 
presence  of  an  organ  of  special  sense  is  certainly  no  evidence 
that  its  activities  are  accompanied  by  Sensation.     What  we 
call  an  organ  of  special  sei:se  is  an  organ  ailapted  to  respond 
to  a  special  form  of  stimulation ;  l»ut  whether  or  not  the  pro- 
cess  of  response   is  accompanied   by  a   sensation  is  quite 
another  matter.     We  infer  by  a  strong  analogy  that  it  is  so 
accompanied  in  the  case  of  organisinn  like  our  own  (whether 
of  men  or  of  the  higher  animals) ;  but  the  validity  of  such 
inference  clearly  dimiuiyhes  with  the  diminishing  strength  of 
the  analogy — i.e.,  as  we  recede  in  the  zookij^ical  and  psycho- 
logical scales  from  organisms  like  our  own  towards  organisms 
less  and  less  like. 

Having  thus  made  it  as  clear  as  I  can  that  it  is  only  for 
the  matter  of  convenience  that  I  have  supjiused  the  rise  of 


Sensation   to   coincide  with    the  rise   of 


organs 


of   special 


*  Altliougli  this  sounds  like  a  tniisui,  it  ia  in  direct  opposition  to  t'le 
classification  of  Lewes,  alluilud  to  aboTe. 


1   lit 


I 


80 


MENTAL   EVOLUTIOxV  IN  ANIMALS. 


r  > 


sense   I  shall  next  proceed  to  take  a  brief  survey  of  the 
s^nse     In"f""  T/^'  reference   to  the   powers   of' speck 
uXshn&p  H    l^^"''^^'''^'''  '^  ''  "^<^^^«'^«'  ^'"1  indeed 

vv hi      iL      -1  /""T"'^''^"   °'"^"«  °f  «P«cial  sensation 
vMiich  the  animal  knigdom  presents.     My  object  is  merely  to 
pve  a  genera  outline  of  the  j  .wers  of  special  sensaZn  pro- 
bably enjoyed  by  different  classes  of  animals;  for,  as  these 
owers  constitute  the  foundation  of  all  the  otl.er  powers  of 
n     IP   if  f?   "^^P°^^^"^«  for  us  to  have  a  general  idJa  of  the 
foolti^il  sS.  ^^^^'^^^P"^-^  "^  ^^-   -"-l^y  g-les  of  the 
In  some  of  his  recently  published  experiments   Enrrel- 
mann  found  tiiat  many  of  the  protoplasmic  and  unicflluhir 
organisms  are  affected  by  light    that  is  to  say,  tlXmove- 
m  n  s  are  influenced  by  light,  in  some  cases  causing  a  cele- 
r  tion  in  others  slowing  of  their  movements ;  in  some  cases 
te  organisms  seeking  the  light,  while  in  other  cases  they 
d  <^    1   V     ••  '^'-     ^?  ^^""'^  ^^'^^  ""^^  t^^e^e  effects  were  re- 
dn?    I    .i"""?  Z  ^^^'f  ''^  ^^'''^  ^''^"■^^^«--  (1)  alteration  pro- 
a  Ipr  Hnr  '  ^t^  "'  the  interchange  of  gases  (2)  consequent 
alteration  m  the  conditions  of  respiration,  and  (3)  specific 
processes  of  luminous  stimulation.     It  is  with  the  latter  o^y 
that  we  are  concerned,  and  tlie  organism  which  Engelmann 
names  as  exhibiting  it  typically  is  Unglena  vrridi^    aC 
piecauions  had  been  taken  to  eliminate  causes  1  and  2  it 
was  still  found  that  this  organism  sought  the  light.     More- 
over, It  was  f;>und  that  it  would  only  do  so  if  the'  light  were 
allowed  to  fall  upon  the  anterior  part  of  its  body     Here 
thrwo  ""  P;»"^^"t-«P'^^'  ^''^  careful  experiment  showed  that 
tnis  was  not  the  point  most  sensitive  to  light,  a  colourless 
^ound'f'?'''"'  'tJ'"  '^  protoplasm  lying  in  fi-oAt  of  it  behig 
tound  to  be  so.     Hence  it  is  doubtful  whether  this  piament^ 
spot  is  or  is  not  to  be  regarded  as  an  exceedingly  prfmitive 
:S^S^:^Se/^  ''''  ''''  ''  '''  spectrliJ:!!.^.^/.. 
The  remarkable  observation  recorded  by  Mr.  H.  J.  Carter, 
di.nlo";''!    "^T       from  Jiim  in  my  previous  work,t  seems  to 
display  almost  incredible  powers  of  special  sense  among  the 

i  Animal  Intelligence,  ^^.  lQ-21. 


J 


II   t 


8ENSATI0N. 


81 


Rhizopoda;  and  Professor  Hreckel  observes,  in  his  essay  on  tlie 
"  Orij^inand  Development  of  the  Sense-Or<rans,"  that  "  already 
among  the  microscopic  Protista  there  aro  some  that  love  light, 
and  some  tliat  love  darkness  rather  than  light.  Many  seem  also' 
to  have  smell  and  taste,  for  they  select  their  food  with  great 
care.  .  .  .  Here  also  we  are  met  by  the  weighty  fact  that 
sense-function  is  possible  without  sense-organs,  without  nerves. 
In  place  of  these,  sensitiveness  is  resident  in  that  wondrous, 
structureless,  albuminous  substance  which,  under  the  name  of 
protoplasm,  or  organic  formative  material,  is  known  as  the 
general  and  essential  basis  of  all  the  phenomena  of  life." 

Again,  Engelmann  describes  a  chase  of  one  infusorium 
by  another.  The  former  in  its  free  course  happened  to  cross 
the  route  of  a  free-swarming  vorticella.  There  was  no  con- 
tact, but  it  immediately  gave  chase,  and  for  five  seconds  the 
two  darted  about  with  the  utmost  activity,  the  chasing  infu- 
sorium maintaining  a  distance  of  about  ^  mm.  behind  the 
chased  one.  Then,  owing  to  a  sudden  sideward  dart  of  the 
vorticella,  its  pursuer  lost  the  object  of  pursuit.  The  powers 
of  discrimination  shown  by  certain  deep-sea  protoplasmic 
organisms  in  selecting  sand-grains  of  a  particular  size  where- 
with to  construct  their  tests  has  already  been  alluded  to. 

But  passing  now  to  animals  in  which  we  first  meet  with 
nerves,  viz.,  the  Medusae,  it  is  among  them  also  that  we  first 
meet  with  organs  of  special  sense.     I  have  myself  observed 
that  several  species  of  Medusie  seek  the  light,  following  a 
lantern  if  this  is  moved  round  a  bell-jar  containing  tliem 
in  a  dark  room.     The  pigmented  bodies  round  the  margin  of 
the  swimming-disk  were  proved  to  be  the  organs  of  special 
sense  here  concerned,  and  the  rays  in  the  spectrum  by  which 
they  are  affected  were  shown  to  be  confined  to  the  luminous 
part.     It  was  further  observed  that  some  genera  of  Medusa; 
had  more  highly  developed  visual  sensation  than  others.    The 
least  efhcient  occurs  in  Tiaropsis  polydiadcmata,  as  shown  by 
the  prolonged  interval  of  delay  between  the  fall  of  a  luminous 
stimulus  and  the  occurrence  of  the  response.     As  the  case  is 
an  interesting  one,  I  shall  state  the  particulars  more  fully. 
This   Medusa,    then,   always   responds   to   strong  luminous 
stimulation  by  going  into  a  spasm  or  cramp ;  but  it  will  not 
respond  at  all  unless  the  liglit  is  allowed  to  fall  upon  its 
sense-organs  for  a  period  of  more  than  one  second ;  if  a  slip- 
shutter  is  opened  and  closed  again  for  a  shorter  period,  no 


!! 


Mi 


llll 


S's 


"  1 


i 


\i  il 


88  MENTAL  EVOI-UTION  IN  ANIMALS. 

response  is  niiule.     It  therefore  seems  certain  that  here  wo 
have  not  to  deal  with  what  physiolo^'ists  call  the  period  of 
latent  stimulation,  but  with  the  time  during  which  the  light 
requires  to  fail  ia  order  to  constitute  an  adequate  stimulus ; 
just  as  a  photographic  plate  requires  a  certain  period  of  expo- 
sure in  order  to  admit  of  the  luminous  vibrations  throwing 
down  the  salt,  so  with  the  ganglionic  material  of  this  sense- 
organ.     How  different  is  the   efficiency  or  development  of 
8uch  a  visual  appsiratus  from  that  of  a  iully  perfected  retina, 
which  is  able  to  effect  the  needful  nervous  changes  in  response' 
to  a  stimulus  as  instantaneous  as  tl'.at  .supplied  by  a  flash  of 
lightning.*     It  is  remarkable,  looking  to  the  Medusa  as  a 
whole,  in  what  a  wonderful  degree  these  primitive  sense- 
organs  vary  as  to  their  minute  structure  in  different  species. 
Nerve-cells  and  fibres,  wrought  up  into  mor^-  or  less  complex 
forms,  are  clearly  discernible  in  all  those  which  have  hitlierto 
been  carefully  examined;  but  when  the  particular  specific 
forms  are  compared  with  one  another,  it  seems  almost  as  if 
organs  of  special  sense,  where  they  first  undoubtedly  occur 
in  the  animal  kingdom,  revel,  as  it  were,  in  the  variety  of 
forms  which  they  are  able  to  present. 

It  is  probable,  from  the  structure  of  the  lithocysts,  that 
the  Meduste  are  also  affected  by  sonorous  vibrations,  and  it 
is  certain  that  they  are  richly  supplied  with  a  variety  of 
organs  ministering  to  the  sense  of  touch.     For  not  only  are 
they  furnished  with  numerous  long,  highly  sensitive,   and 
contractile  tentacles,  but    in    some    species   the    marginal 
ganglia    are    provided  with  minute   hair-like    appendages, 
which  must  enable  the  nerve-cells  to  which  they  are  attached 
to  be  exceedingly  sensitive  to  anything  touching  the  hairs. 
And,  in  connection  with  the  sense  of  touch  in  the  Medusae,  I 
may  allude  to  my  own  observations  on  the  precision  with 
which  the  point  of  contact  of  a  foreign  body  is  localized. 
A  Medusa  being  an  umbrella-shaped  animal,  in  which  the 
whole  of  the  surface  of  the  handle  tuid  the  whole  of  the  con- 
cave surface  of  the  umbrella  is  sensitive  to  all  kinds  of  stimu- 
lation,  if   any  point  in  the  last-named  surface  is  gently 
touched  with  a  camel-hair  brush   or  other  soft  (or  hard) 

*  For  a  full  account  of  these  experimenta,  see  Phil.  Trans.,  vol.  166, 
Pt.  I,  Croonian  Lecture,  where  it  is  shown  that  in  other  species  of  Medus®! 
the  seiise-orgaus  of  vvliich  are  more  highly  developed,  there  is  no  such  pro- 
longed delaj  in  the  response  to  luminous  stimulation. 


SENSATION. 


88 


object,  the  handle  or  inaniibrium  is  (in  the  case  of  many 
species)  immediately  moved  over  to  that  point,  in  order  to 
examine  or  to  brush  away  the  foreign  body.  Tliis  is  especially 
the  case  in  a  species  which  for  this  reason  I  have  called 
Tiaropsis  indicans;  and  hero  it  is  of  interest  to  observe  that 
if  the  nerve-plexus,  which  is  spread  all  over  the  concave  sur- 
face of  the  umbrella,  is  divided  by  means  of  an  incision 
ca    ied  in  the  form  of  a  short  straight  line  parallel  to  the 
margi     of  the  umbrella,  and  if  a  point  below  the  line  of 
incision  is  touched,  the  manubrium  is  no  longer  able   to 
localize  the  seat  of  contact.     Nevertheless  it  feels  that  con- 
tact is  taking  place  someivherc,  for  it  begins  actively  to  dodge 
about  from  side  to  side  of  the  umbrella,  applying  its  ex- 
tremity now  to  one  point  and  now  to  another  of  the  umbrella 
surface,  as  if  seeking  in  vain  for  the  offending  body.     This  of 
course  shows  that  tlie  stimulus,  on  reaching  the  ends  of  the 
severed    nerve-fibres,    spreads   through   the   general    nerve- 
plexus,  and  so  arriving  at  the  manubrium  by  a  number  of 
different  routes,  conveys  a  corresponding  number  of  conflict- 
ing messages   to   the  manubrium   as  to   the   point  in  the 
umbrella  at  which  the  stimulus  is  being  ap])lied.     This  irra- 
diation   of    a   stimulus    into   other    nerve-fibres   when   the 
stimulus  reaches  the  cut  ends  of  the  fibres  which  constitute 
the  habitual  route  of  a  stimulus  between  two  points,  is  ren- 
dered the  more  interesting  from  the  fact  that  in  the  case  of 
the  external  nervous  plexus  of  the  Echinodermata  there  is  no 
vestige  of  such  a  plieuomenon. 

So  much  for  the  senses  of  sight  (at  least  to  the  extent  of 
distinguishing  light  from  darkness),  hearing,  and  touch,  as 
localized  in  organs  of  special  sense  among  the  Medusae.  In 
the  allied  Actiniie  Mr.  Walter  Pollock  and  myself  have  ob- 
tained conclusive  evidence  of  the  sense  of  smell.  For  we 
found  that  when  a  morsel  of  food  is  dropped  into  a  pool  or 
tank  containing  sea-anemones  in  a  closed  state,  the  animals 
quickly  expand  their  tentacles.*  It  has  been  said  that  this 
may  be  taken  to  argue  a  sense  of  taste  no  less  than  a  sense  of 
smell ;  but  I  conceive  that  here  no  distinction  can  be  drawn 
betvyeen  these  two  senses,  any  more  than  we  can  draw  such  a 
distinction  in  the  analogous  case  of  fish.  Looking,  then,  to 
the  Ccelenterata  as  a  whole,  we  find  that  where  we  first  meet 
with  unmistakeable  oigans  of  special  sense,  we  also  first  meet 
•  See  Journal  Linnean  Society,  1862, 


Mi 


if 


:m 


IMAGE  EVALUATION 
TEST  TARGET  (MT-3) 


1.0 


I.I 


1.25 


yo    ™^™ 

us 

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lAP 


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Photographic 

Sciences 

Corporation 


23  WEST  MAIN  STREET 

WEBSTER,  NY.  14580 

(716)  872-4503 


t-^' A  «P!* 


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n>-^ 


) 


84 


MENTAL  EVOLUTION  IN  ANIMALS. 


;i 


with  uninistakeable  evidence  of  the  occurrence  of  nil  i\..  « 
of  distiuo'in'qhin.T   1,-rri.f   f         J    -  J^^^  uueiius,  capable  onlv 


I 


SENSATION. 


85 


not  correct.    "We  do  not  really  see  things  reversed,  for  the 
inind  IS  not  a  perpendicular  object  in  space,  standing  behind 
the  retina  in  the  manner  that  a  photographer  stands  behind 
his  camera.    To  the  mind  there  is  no  up  or  down  in  the 
retina,  except  in  so  far  as  the  retina  is  in  relation  to  the 
external  world ;  and  this  relation  can  only  be  determined 
not  by  sight,  but  by  touch.    And  if  only  this  relation  is 
constant,  it  can  make  no  difference  to  the  mind  whether  the 
images  are  direct,  reversed,  or  thrown  upon  the  retina  at  any 
angle  with  reference  to  the  horizon ;  in  any  case  the  corre- 
lation between  sight  and  touch  would  be  equallv  easy  to 
establish,  and  we  should  always  see  things,  not  in  the  position 
m  which  they  are  throivn  upon  the  retina,  but  in  that  which 
they  occupy  with  reference  to  the  retina.    Thus  it  reaUy  re- 
quires no  more  'practice'  correctly  to  interpret  inverted 
images  than  it  does  similarly  to  interpret  upright  images  • 
and  therefore  the  fact  that  some  eyes  of  an  ant  are  sup- 
posed to  throw  direct  images,  while  others  are  supposed  to 
throw  inverted,  is  not  any  real  objection  to  the  theorv' 
that  they  do.*  *' 

There  is  no  one  group  in"  the  animal  kingdom  where  we 
have  so  complete  a  series  of  gradations  in  the  evolution  of  an 
organ  of  special  sense  as  is  presented  by  the  organ  of  sif^ht  in 
Worms     "In  the  lowest  Vermes,"— I  quote  from  Prolessor 
Hseckelf— "the  eye  is  only  made  up  of  individual  pigment-cells. 
In  others,  refractive  bodies  are  associated  with  these,  and  form' 
a  very  simple  lens.     Behind  these  refractive  bodies  sensory 
cells  are  developed,  forming  a  retina  of  the  simplest  order 
presenting  a  single  layer,  the  cells  of  which  are  in  connection 
with  extremely  delicate  terminal  fibres  of  the  optic  nerve. 
Lastly,  in  the  Alcipidse,  which  are  highly  organized  Annelidte 
that  swim  on  the  surface  of  the  sea,  adaptation  to  this  mode 
of  life  has  brought  about  such  perfection  of  the  eye  that  this 
organ  in  these  animals  is  in  no  way  inferior  to  that  of  the 
lower  vertebrata.     In  these  creatures  we  find  a  large  globular 
eye-ball,  enclosing  externally    a    laminated  globular  lens, 
internally  a  vitreous  body  of  large  circumference.     Imme- 
diately investing  these  are  rods  of  the  usual  cells  sensitive  to 
light,  which  are  separated  by  a  layer  of  pigment-cells  from 
the  outer  expansion  of  the  optic  nerve  or  retina.     The  ex- 

•  Quoted  from  an  article  of  my  own  in  Nature,  June  8, 1882. 
t  Jissai/  on  Origin  and  Development  of  Sense-oi-yuns. 


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86 


MENTAL  EVOLUTION  IN  ANIMALS. 


ternal  epidermis  invests  the  whole  of  the  prominent  eve-ball 
and  forms  m  front  of  it  a  transparent  hor^^  layer  S 
cornea."  Further,  from  the  more  recent  obTervaSs  o 
Mr.  Darwin,  it  is  certain  that  Earthworms,  althouXSLte 
of  eyes,  are  able  to  distinguish  with  much  rar.idf/v  n?rf  n^! 
cisi^n  between  light  and  da^knes^;  IHs  helunJthat  ft  s" 
only  the  anterior  extremity  of  the  animal  which  disp  avs  this 

S^^/H•^'  r"'^^^'.\^*^"*  '^'  ^'Sht  affects  the  antS  Janaha 
immediately,  or  without  the  intervention  of  a  sense-Sr  "an  * 
Lastly,  Schneider  says  that  Serpul^  will  suddenly  withdraw 
their  expanded  tufts  when  a  shadow  falls  upon  them  but  th^ 
shadow  must  be  that  of  an  object  moving  wfth  some  r^^^^^^ 

Turmng  now  to  the  sense  of  hearing  in  the  ArticXta  wl 
find  the  simplest  type  of  ear  among  %he  Vermes  where  i? 
occurs  as  a  closed  globular  vesicle  containing  S  rwhich 
there  is  suspended  an  otolith  +  In  snmp  iS  fhln  7 
such  as  theWfish  and  lobster  th^Tgat  of\''eTri^^^^^^^ 
much  more  complex,  and  here,  "if  we  give  rise,  by  plS' 

Ob  e^e  the  :.d7/"  ''  ^^W  Pitch,  afd  at  the  sLfS 
Observe  the  aaditory  organ  under  the  microscope,  we  see  that 

ttn  'f  At  '"\^  '  r'^'^^^  ^""^^'^y  ^'^  i«  seT  in  vib  a- 
tion  §    Among  Insects  organs  of  hearing  certainly  occur  at 
least  m  some  species,  although  the  experWents  of  sHibn 
Lubbock  appear  to  show  that  ants  are  deaf.     The  evidence 
that  some  insects  are  able  to  hear  is  not  only  moXloS 
but  also  physiological,  because  it  is  only  on  the  sSnnnJHnn 
hat  they  do  that  the  fact  of  stridulatiL  and  otlXTeS 
sounds  being  made  by  certain  insects  can  be  expkSed    and 
Brunelh  found  that  when  he  separated  a  female  gZho^ 
from  the  male  by  a  distance  of  several  metrertierairbTan 
to  stridulate  m  order  to  inform  hpr  nf  iiia  '^''rt'^^^  "^S^^ 
which  the  female  app:«ache?S.||'"l  C  mS^ubS 
observations  proving  the  occurrence  of  a  sense  orhearino 
among  the  Lepidoptera.f    Turning  to  the  moZolticS 
of  the  subject,  it  is  remarkable  iat  in  the  ArSafa  the 


SENSATION. 


87 


ii 


auditory  organs  occur  among  different  members  of  the  group 
in  widely  different  parts  of  "the  body.  Thus  in  the  lobster 
and  cray-fish  they  are  situated  in  the  head  at  the  base  of  the 
antennules,  while  in  some  of  the  crabs  {e.g.,  Mysis)  they  occur 
in  the  tail.  Among  the  Orthoptera,  again,  they  are  found  in 
the  tibiae  of  the  front  legs,  or,  in  other  species,  upon  the  sides 
of  the  thorax.  In  other  insects,  probability  points  to  the 
organs  of  hearing  being  placed  in  the  antennae.  These  facts 
prove  that  in  the  Articulata  the  sundry  kinds  of  auditory 
organs  must  have  arisen  independently,  and  have  not  been 
inherited  from  a  common  ancestor  of  the  group ;  and  it  is 
remarkable  that  this  should  have  been  the  case  even  within 
the  limits  of  so  comparatively  small  a  subdivision  as  that 
which  separates  a  crab  from  a  crayfish  or  a  lobster.* 

There  can  be  no  question  that  the  sense  of  smell  is  well 
developed  in  at  least  many  of  the  Articulata,  although,  save 
in  a  few  cases,  we  are  not  yet  in  a  position  to  deteimine  the 
olfactory  organs.     Thus  the  account  which    I    quoted  in 
I' Animal  Intelligence"  (p.  24),  from  Sjt  E.  Tennent,  concern- 
ing the  habits  of  the  land  leeches  of  Ceylon,  proves  that 
these  animals  must  be  accredited  with  a  positively  astonishino- 
delicacy  of  olfactory  perception,  seeing  that  they  smell  the 
approach  of  a  horse  or  a  man  at  a  long  distance.     In  earth- 
worms the  sense  of  smell  is  feeble,  and  seems  to  be  confined 
to  certain  odours.f    Sir  John  Lubbock  has  proved  by  direct 
experiment  that  ants  are  able  to  perceive  odours,  and  that 
they  appear  to  do  so  by  moans  of  their  antennae.    The  same 
remark  applies  to  bees,  and  the  general  fact  that  many  insects 
can  smell  is  shown  by  the  general  fact  that  so  many  species 
of  flowering  plants,  which  depend  for  their  fertilization  upon 
the  visits  of  insects,  give  out  odours  to  attract  them.     That 
the  Crustacea  are  able  to  smell  is  rendered  evident  by  the 
rapidity  with  which  they  find  food.     I  have  recently  been 
able  to  localize  the  olfactory  organs  of  crabs  and  lobsters  by 
a  series  of  experiments  which  I  have  not  yet  published,  and 
which  would  occupy  too  much  space  here  to  detail.     I  shall 
therefore  merely  say  that  they  are  situated  in  the  pair  of 
small  antennules,  the  ends  of  which  are  curiously  modified  in 
order  to  perform  the  olfactory  function.    That  is  to  say,  the 

*  Analogoiis  facta  are  to  be  observed  in  the  case  of  the  Eye  among 
Vermes,  and  also,  as  we  shall  presently  aee,  among  Mollusca. 
t  Darwin,  loc.  cit.,  p.  30. 


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88 


MENTAL  EVOLUTION  IN  ANIMALS, 


terminal  joint  works  in  a  vertical  plane,  and  supports  the 
sensory  apparatus,  which  is  kept  in  a  perpetual  jerking  motion 
np  and  down,  so  as  to  bring  that  apparatus  into  sudden  con- 
tact with  any  minute  odoriferous  particles  which  may  be  sus- 
pended in  the  water— just  on  the  same  principle  as  we  our- 
selves smell  by  taking  a  number  of  small  and  sudden  sniffs 
01  air.  Any  one  visiting  an  aquarium  can  have  no  difficulty 
m  observing  these  movements  upon  any  crab  or  lobster  in  a 
healthy  condition. 

The  sense  of  taste  certainly  occurs  at  least  among  some 
species  of  the  Articulata  (as,  e.f/.,  among  the  honey-feedincr 
insects)  and  the  sense  of  touch  is  more  or  less  elaborately 
provided  for  m  all.  "^ 

Turning  now  to  the  MoUusca,  we  pass  in  a  tolerably 
unitorm  series  from  the  simple  eye-spots  of  certain  of  the 
Lamellibranchiata,  through  the  Pteropoda,  to  the  more  com- 
pletely organized  eyes  of  the  Gasteropoda  and  the  Heteropoda. 
13ut  when  we  arrive  at  the  Cephalopoda,  we  encounter,  as  it 
were,  a  vast  leap  of  development;  for  the  eye  of  an  octopus 
in  point  of  organization,  is  equal  to  that  of  a  fish,  which  it 
so  closely  resembles.    And,  while  remembering  that    the 
resemblance,  striking  though  it  be,  is  only  superficial,  we  must 
not  tail  to  note  that  this  enormous  development  in  the  organi- 
zation of  the  molluscous  eye,  which  brings  it  so  strangely  to 
resemble  the  eye  of  a  fish,  is  clearly  correlated  with  the  no 
less  enormous  development  of  the  neuro-muscular  system  of 
the  animal  m  which  respect  it  more  resembles  a  fish  than  it 
does  the  other  Mollusca.     This  case  is  therefore  analogous  to 
the  similarly  high  development  which  has  been  attained  by 
the  eye  of  the  swimming  worm  previously  described 

If  we  look  to  the  Mollusca  as  a  class,  we  meet  with  the 
same  kind  of  variation  in  the  position  of  the  eye  which  we 
have  already  noticed  with  respect  to  the  ear  in  the  Articulata 
Ihus,  while  m  the  Cephalopoda  and  Gasteropoda  the  eyes 
a,re  situated  m  the  head,  in  some  of  the  latter  group  there 
are  supplementary  eyes  upon  the  back,  which  greatly  differ 
in  structure  from  the  eyes  in  the  head.  In  the  LampUi- 
branchiata,  again,  the  eyes  occur  in  large  numbers  on  the 
margin  of  the  mantle. 

The  sense  of  hearing  is  general  to  all  the  Mollusca,  and 
the  auditory  organs  exhibit  a  progressive  elaboration  as  we 
ascend  from  the  lower  to  the  higher  groups,  which  is  analo- 


SENSATION. 


89 


goTis  to  that  already  noticed  with  reference  to  the  organs  of 
sight.  Thus,  among  the  lower  Mollusca  the  organs  of  hearing 
consist  of  a  pair  of  small  vesicles  attached  to  auditory 
nerves,  and  filled  with  fluid  in  which  an  otolith  is  suspended. 
In  the  Cephalopoda,  however,  while  the  same  general  plan  of 
structure  is  adhered  to,  we  find  an  approximation  to  the 
auditory  apparatus  of  a  fish ;  for  the  vesicle  or  sac  is  now 
embedded  in  the  cartilage  of  the  head,  is  of  larger  size,  and 
in  general  analogous  to  the  organ  of  hearing  of  the  Verte- 
brata.  That  at  all  events  the  majority  of  the  Mollusca  are 
able  to  smell,  is  proved  by  the  readiness  with  which  they  find 
food,  and  the  octopus  is  said  to  show  a  strong  aversion  to 
certain  odours  (Marshall).  In  the  Cephalopoda  the  olfactory 
organs  are  probably  two  small  cavitios  near  the  back  of  the 
eye,  and  in  the  other  Mollusca  they  are  surmised  to  be  situated 
in  the  small  tentacles  near  the  mouth.  Touch  is  provided 
for  both  by  these  and  by  the  larger  tentacles  (as  well  as  by 
the  general  soft  exterior)  ;  but  in  the  Cephalopoda  by  the  long, 
snake-like  arms,  which  I  think  must  be  regarded  as  giving 
these  animals  a  greater  power  of  receiving  tactile  impressions 
than  is  enjoyed  by  any  other  marine  animal. 

Among  Fish  sight  is  well  developed.  A  trout  will  dis- 
tinguish a  worm  suspended  in  muddy  water ;  a  salmon  can  • 
avoid  obstacles  when  swimming  with  immense  velocity  ;  and 
a  Chelmon  rostratus  can  take  unerring  aim  with  its  little 
water  projectile  at  a  fly.  The  blind  fish,  which  live  habitually 
in  the  dark,  have  lost  their  eyes  merely  from  disuse  ;  but  in 
this  connection  it  must  be  noted  that  we  meet  with  a  curious 
biological  puzzle  in  the  case  of  many  of  the  deep  sea  fishes 
dredged  by  the  Challenger.  For  although  living  at  depths  to 
which  no  light  can  be  supposed  to  penetrate,  some  of  these 
fisli  have  large  eyes.  It  may  be  suggested  that  the  use  of 
these  eyes  is  that  of  seeing  the  many  self-luminous  forms  of 
life  which,  as  the  Challenger  dredgings  also  show,  inhabit  the 
deep  sea.  But  if  this  is  suggested,  the  question  immediately 
arises  as  to  why  these  forms  have  become  luminous ;  for  if 
thus  rendered  conspicuous  to  the  fish,  their  luminosity  must  so 
far  be  a  disadvantage  to  them.  In  the  case  of  the  lumi- 
nous animals  which  themselves  have  eyes,  we  may  suppose 
that  this  disadvantage  is  more  than  compensated  for  by  the 
advantage  of  enabling  the  sexes  to  find  each  other;  but  thia 
explanation  does  not  apply  to  the  blind  forms. 


!     HI 


90 


MENTAL  EVOLUTION  IN  ANIMALS. 


Fish,  as  we  have  already  observed,  are  well  provided  with 
the  organs  both  of  hearing  and  of  smell,  Amphioxus  being  the 
only  member  of  the  class  which  is  destitute  of  ears,  and  the 
oltactory  lobes  in  the  case  of  some  species  {e.g.,  the  Skate) 
being  of  enormous  size  in  relation  to  the  other  parts  of  the 
brain.    The  sense  cf  touch  is  provided  for  in  many  species 
by  tentaculse  in  the  neighbourhood  of  the  mouth.    The  soft 
lips,  and  m  some  species  the  pectoral  fins,  are  also  tactile  in 
lunction,  and  in  certain  gurnards  there  are  digitate  appendages 
connected  with  the  latter  which  doubtless  serve  to  increase 
their  efficiency  as  organs  of  touch.    It  is  doubtful  whether 
taste,  as  distinct  from  smell,  occurs  in  fish;  but  we  must 
reinember,  as  before  observed,  that  in  the  case  of  an  aquatic 
animal  there  is  no  true  distinction  to  be  drawn  between  these 
two  senses.    For  as  there  is  here  no  gaseous  medium  (like 
the  air)  m  question,  the  only  distinction  that  can  be  drawn  is 
a^  to  whether  the  nerve  terminations,  which  are  affected  bv 
the  suspended  particles  in  the  water,  happen  to  be  dis- 
tributed over  any  part  of  the  mouth  where  the  food  passes 
or  over  any  other  part  of  the  animal.     I  say  over  any  other 
part  of  the  animal  (and  not  only  in  the  nasal  fosste),  because 
m  some  species  of  fish  there  are  embedded  in  the  skin  along 
the  sides  of  the  body  a  number  of  curiously-formed  papilla 
which  on  morphological  grounds  may  reasonably  be  regarded 
as  ministering  to  the  sense  of  smell,  or,  as  we  may  indifferently 
call  It,  of  taste.    Hackel,  however,  speculates  upon  these 
organs,  and  is  inclined  to  think  that  they  minister  to  some 
unknown  sense. 

The   sense  of  sight  in  Amphibia  and    Reptiles  offers 
nothing  specially  worthy  of  remark,  except  that  the  crystal- 
line lens  has  not  so  high  a  refracting  power  as  in  Fish     The 
transition  from  an  eye  adapted  to  see  under  water  and  an  eye 
adapted  to  see  in  air,  appears  to  be  curiously  shown  by  one 
and  the  same  eye  in  the  case  of  the  Surinam  Sprat.     This 
animal  has  its  eyes  placed  on  the  top  of  its  head,  so  that 
when  It  comes  to  the  surface  of  the  water  part  of  the  eyes 
come  into  the  air,  and  "the  pupU  is  partly  divided,  and 
the  lens  is  also  composed  of  two  portions,  so  that  it  is 
supposed  that  one  part  of  this  curious  eye  is  adapted  for 
aerial,  and  the  other  for  aquatic,  vision."*     The  senses  of 
hearing,  smell,  taste,  and  touch,  although  all  present  in  the 

•  Marshall,  Outlines  of  Fi.i/sioloff^,  vol.  i,  p.  603. 


SENSATION. 


91 


Amphibia  and  Reptiles,  are  not  much,  if  at  all,  in  advance  of 
these  senses  as  they  occur  in  Fish. 

Among  Birds  the  sense  of  sight  is  proverbially  keen,  and 
in  point  of  fact  the  animal  kingdom  has  no  parallel  to  the 
excellence  of  the  organ  of  vision  as  it  occurs  in  some  species 
of  this  class.  Whether  we  consider  the  eye  of  a  Hawk,  which 
is  able  to  distinguish  from  a  great  height  a  protectively 
coloured  animal  from  the  surface  of  the  ground  which  it  so 
closely  imitates  ;  or  the  eye  of  a  Solen  Goose,  which  is  able 
from  a  height  of  a  hundred  feet  in  the  air  to  see  a  fish  at  the 
depth  of  many  fathoms  in  the  water ;  or  the  eye  of  a  Swift, 
which  is  able  so  suddenly  to  form  its  adjustments ;  we  must 
alike  conclude  that  the  visual  apparatus  has  attained  to  its 
highest  perfection  among  birds.  And  in  this  connection  it  is 
of  interest  to  note  that  protective  colouring  has  attained  its 
highest  degree  of  perfection  among  animals  which  constitute 
the  prey  of  birds.  So  surprising,  indeed,  is  the  perfection  to 
which  protective  colouring  has  attained  in  some  of  these 
cases,  that  it  has  been  adduced  as  a  difficulty  against  the 
theory  of  evolution ;  for  it  seems  incredible  that  such  perfec- 
tion should  have  been  attained  by  slow  stages  through  natural 
selec^on  before  the  species  exhibiting  it  had  been  extermi- 
nated by  the  birds.  The  answer  to  this  difficulty  is  that 
the  visual  organs  of  the  birds  cannot  be  supposed  to  have 
been  always  so  perfect  as  they  are  now,  and  therefore  that  a 
degree  of  protective  colouring  which  might  have  afforded 
efficient  protection  at  an  earlier  stage  in  the  evolution  of 
those  organs  would  not  supply  such  protection  at  the  present 
day.  In  other  words,  the  evolution  of  the  eyes  of  birds  and 
«f  the  protective  coloration  of  their  prey  must  be  supposed 
to  have  progressed  pari  passu,  each  stage  in  the  one  acting 
as  a  cause  in  the  succeeding  stage  of  the  other.  The  crystal- 
line lens  is  flat  in  birds  which  are  remarkable  for  long  sight, 
such  as  the  vulture ;  rounder  in  owls,  which  are  very  near- 
sighted ;  and  becomes  progressively  more  spherical  in  aquatic 
birds,  according  to  their  aquatic  habits. 

All  birds  are  able  to  hear,  and  it  is  in  this  class  that  we 
first  meet  with  definite  evidence  of  an  ear  capable  of  appre- 
ciating with  delicacy  differences  of  pitch.  Among  many 
species  of  birds  the  delicacy  of  such  appreciation  (as  well  as 
that  of  timhre)  is  so  remarkable  that  it  may  be  questioned 
whether  even  human  ears  are  more  efficient  in  this  respect. 


.'  la 


ii 


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H. 


«>|  ;  • 


92 


MENTAL  EVOLUTION  IN  ANIMALS. 


The  anatomical  difficulty  of  accounting  for  this  fact  I  need 
not  wait  to  consider.  I  am  myself  inclined  to  think  that  the 
sense  of  hearing  in  birds  (at  all  events  of  some  species)  is 
likewise  higlily  delicate  with  reference  to  the  intensity  of 
sound.  My  reason  for  so  thinking  is  that  I  have  observed 
Curlews  dig  their  long  bills  up  to  the  base  into  smooth 
unbroken  surfaces  of  sea-sand  left  bare  by  the  tide,  in  order 
to  draw  up  the  concealed  worms.  Under  such  circumstances 
no  indication  can  be  given  by  the  worm  of  its  position  to  any 
other  sense  of  tlie  curlew  than  that  of  hearing.  Similarly,  I 
suspect  that  the  common  Thrush  is  guided  to  the  worm  buried 
beneath  tlie  turf  by  the  sense  of  hearing,  and  my  suspicion  is 
founded  on  the  peculiar  habits  of  feeding  shown  by  the  bird, 
which  I  have  described  elsewhere.* 

The  sense  of  smell  in  Birds  is  in  advance  of  that  of 
Eeptiles,  but  not  to  be  compared  with  its  excellency  in 
Mammals;  for  the  old  hypothesis  that  vultures  find  their 
prey  by  the  aid  of  this  sense  has  been  abundantly  disproved.f 
The  sense  of  taste  in  Birds  is  likewise  very  obtuse  as  com- 
pared with  this  sense  in  Mammals ;  and  as  compared  with 
the  same  class  they  are  also  defective  in  their  organs  of 
touch.  Indeed,  the  parrot  tribe  is  the  only  one  in  which 
this  sense  is  well  or  specially  provided  for,  except  the  ducks, 
snipes,  and  other  mud-feeding  species,  in  which  the  bill  is 
specially  modified  for  this  purpose. 

If  we  regard  Mammals  as  a  class  we  must  say  that,  with 
the  exception  of  the  sense  of  vision  which  readies  its 
greatest  supremacy  in  Birds,  all  the  special  senses  are  more 
highly  developed  than  in  any  other  class.  This  is  more 
particularly  the  case  with  the  senses  of  smell,  taste,  and 
touch. 

The  sense  of  smell  reaches  its  highest  perfection  among 
the  Carnivora  and  the  Ruminants,  and,  on  the  other  hand,  is 
totally  absent  in  some  of  the  Cetacea.  Any  one  accustomed 
to  deer-stalking  must  often  have  been  astonished  at  the  pre- 
cautions which  it  is  needful  to  take  in  order  to  prevent  the 
game  from  getting  the  "  wind  "  of  the  sportsman ;  indeed  to 
a  novice  such  precautions  are  apt  to  be  regarded  as  implying 
a  superstitious  exaggeration  of  the  possibilities  of  the  olfac- 

*  Nature,  vol.  xv,  pp.  177  and  292,  where  also  see  in  more  detail  my 
observations  on  the  feeding  habits  of  the  curlew, 
t  See  Animal  Intelligence,  pp.  286-7. 


BENSATION. 


93 


tory  sense  ;  and  it  is  not  until  he  has  himself  seen  the  deer 
scent  him  at  some  almost  incredible  distance  that  he  lends 
himseli'  without  disguised  contempt  to  the  discretion  of  the 
keeper.  But  among  the  Carnivora  the  sense  of  smell  is  even 
more  extraordinary  in  its  development  on  account,  no  doubt, 
of  its  being  here  of  so  much  service  in  tracking  prey.  I 
once  tried  an  experiment  with  a  terrier  of  my  own  which 
shows,  better  than  anything  that  I  have  ever  read,  the  almost 
supernatural  capabilities  of  smell  in  Dogs.  On  a  Bank 
holiday,  when  the  broad  walk  in  Eegent's  Park  was  swarm- 
ing with  people  of  all  kinds,  walking  in  all  directions,  I  took 
my  terrier  (which  I  knew  had  a  splendid  nose,  and  could 
track  me  for  miles)  along  the  walk,  and,  when  his  attention 
was  diverted  by  a  strange  dog,  I  suddenly  made  a  number  of 
zig-zags  across  the  broad  walk,  then  stood  on  a  seat,  and 
watched  the  terrier.  Finding  I  had  not  continued  in  the 
direction  I  was  going  when  he  left  me,  he  went  to  the  place 
where  he  had  last  seen  me,  and  there,  picking  up  my  scent, 
tracked  my  footsteps  over  all  the  zig-zags  I  had  made  until 
he  found  me.  Now  in  order  to  do  this  he  had  to  distinguish 
my  trail  from  at  least  a  hundred  others  quite  as  fresh,  and 
many  thousands  of  others  not  so  fresh,  crossing  it  at  all  angles. 

Such  being  the  astonishing  perfection  of  smell  in  dogs,  it 
has  been  well  observed  that  the  external  world  must  be  to 
these  animals  quite  different  from  what  it  is  to  us ;  the 
whole  fabric  of  their  ideas  concerning  it  being  so  largely 
founded  on  what  is  virtually  a  new  sense.  But  in  this  con- 
nection I  may  point  out  that  speculation  on  such  a  subject  is 
shown  to  be  useless  by  the  fact  that  the  sense  of  smell  in 
dogs  does  not  appear  to  be  merely  our  own  sense  of  smell 
greatly  magnified.  For  if  this  were  the  case  it  seems  incredible 
that  highly  bred  sporting-dogs,  which  have  the  finest  noses, 
should  be  those  which  take  the  keenest  pleasure  in  rolling  in 
filth  which  literally  stinks  in  our  nostrils  to  the  degree  of 
being  physically  painful. 

The  sense  of  hearing  is  acute  in  Mammals  as  a  class,  and 
it  is  worthy  of  remark  that  this  is  the  only  class  provided 
with  movable  ears.  As  Paley  observes,  in  beasts  of  prey  the 
external  ear  is  habitually  directed  forwards,  while  in  species 
which  they  prey  upon  the  ear  admits  of  being  directed  back- 
wards. With  the  exception  of  the  singing  monkey  (Hi/lobates 
agilis),  there  is  no  evidence  of  any  mammal  other  than  man 
7 


:|ii 


¥ 


),' 


■    i 


J 


I 


I  III 


11'!-:; 


MENTAL  EVOLUTION  IN  ANIMALS. 


94 

havin{»  any  delicate  perception  of  pitch.  I  have,  however, 
heard  a  tenier,  wliich  used  to  accompany  a  song  by  howling, 
follow  the  prolonged  notes  of  the  human  voice  with  some 
approximation  to  unison  ;  and  Dr.  Huggins,  who  has  a  good 
ear,  tells  mo  that  his  large  mastiff  "  Kepler  "  used  to  do  the 
same  to  prolonged  notes  sounded  from  an  organ. 

The  sense  of  taste  is  much  more  highly  developed  in  the 
Mammalia  than  in  any  other  class,  and  the  same  general 
statement  applies  to  the  sense  of  touch.  Looking  to  tlie 
class  as  a  whole,  the  principal  organs  of  the  latter  are  the 
snout,  lips,  and  tongue ;  the  modified  hairs,  or  "  whiskers," 
are  also  very  generally  present.  Among  the  Kodents,  some  of 
the  Mustelido!  and  all  tlie  Primates,  the  principal  organs  of 
touch  are  the  hands.  And  it  would  appear  that  the  extreme 
modification  which  these  members  have  undergone  in  the 
Cheiroptera  has  been  attended  with  an  extraordinary  exalta- 
tion of  their  power  of  tactile  sensation.  For  m  the  celebrated 
experiment  of  Spallanzani  (since  repeated  and  confirmed  by 
several  other  observers),  it  was  found  that  when  a  Bat  is 
deprived  of  its  eyes,  and  has  its  ears  stopped  up  with  cotton- 
wool, it  is  still  able  to  fly  about  without  apparent  inconveni- 
ence, seeing  that  it  avoids  all  obstacles  in  its  flight,  even 
though  these  be  but  slender  strings  stretched  through  the 
room  in  which  the  animal  is  allowed  to  fly.  The  only  expla- 
nation of  this  surprising  fact  is  that  the  membranous 
expanse  of  the  wing,  which  is  richly  supplied  with  nerves, 
has  developed  a  sensibility  to  touch,  to  temperature,  or  to 
both,  so  extreme  as  to  inform  the  bat  of  the  proximity  of  a 
solid  body  even  before  contact — either  through  the  increase 
in  the  air-pressure  as  the  wing  rapidly  approaches  the  solid 
body,  or  through  the  difference  in  the  exchange  of  heat 
between  the  wing  and  the  solid  as  compared  with  such  ex- 
change between  the  wing  and  the  air.  When  groping  our  way 
through  a  dark  room  we  are  ourselves  able  to  feel  a  large 
solid  body  (such  as  a  wall)  before  we  actually  touch  it, 
especially,  I  have  observed,  with  the  skin  of  the  face.  Pro- 
bably, therefore,  it  is  a  great  exaltation  of  this  power  which 
enables  these  night-flying  animals  to  avoid  so  slender  a  solid 
body  as  a  stretched  string.  But  when  we  remember  the 
rapidity  and  accuracy  with  which  the  sensation  must  here  be 
aroused,  we  may  well  consider  it  ta  equal,  if  not  to  surpass, 
in  the  domain  of  touch,  the  evolutionary  development  of 


i 


;tt 


1   \l 


SENSATION. 


95 


1  fii  '. ' 


Bense-organs  as  it  occurs  in  the  sight  of  tho  vultiim  or  tlie 
smell  of  the  dog.  Indeed,  Hceckel  and  others  have  specu- 
lated whether  the  facts  in  this  case  do  not  call  for  the  suppo-' 
eition  of  some  additional  and  unknown  sense,  different  in 
kind  from  any  that  we  ourselves  possess.  But  I  think  it  is 
safer  not  to  run  into  any  such  ohscure  hypothesis  unless 
actually  driven  to  do  so,  and  therefore  I  shall  not  here  enter- 
tain it.  For  this  reason,  also,  I  shall  not  follow  H.Tckel  in 
his  view  that  the  "homing"  faculty  of  certain  animals  is  due 
to  some  additional  and  inexplicable  sense,  and  therefore  I 
shall  reserve  my  treatment  of  this  topic  for  my  chapters  on 
Instinct. 


After  this  rapid  survey  of  the  powers  of  Special  Senpe  as 
they  severally  occur  in  different  classes  of  the  animal  kiuf;- 
dom,  I  shall  conclude  the  present  chapter  by  brieHy  consider- 
ing certain  general  principles  connected  with  Sensation. 

The  muscular  sense,  the  sense  of  hunger,  thirst,  satiety, 
and  others  of  the  like  general  kind  need  not  detain  us ;  for 
although  their  causation  is  somewhat  obscure,  we  know  at 
least  that  they  are  dependent  upon  nervous  adjustments, 
and,  being  of  so  much  importance  to  animals,  we  infer  that 
they  have  been  developed  under  the  general  principles  of 
neuro-muscular  evolution  already  considered  in  previous 
chapters.  My  object  here  is  rather  to  consider  the  mecha- 
nisms of  certain  more  special  senses  from  the  point  of  view 
of  those  general  principles. 

First  as  to  the  sense  of  Temperature,  there  is  good  evi- 
dence that  in  ourselves  and  at  least  in  all  the  higher  animals, 
thermal  sensations  can  only  be  received  by  the  nerve-endings 
in  the  skin  and  adjacent  parts  of  the  mucous  membranes  ;  if 
the  nerve-libres  immediately  above  their  terminations  in 
these  localities  (as  in  the  raw  surface  of  a  wound)  be  stimu- 
lated by  heat  or  cold,  the  sensation  produced  is  merely  one 
of  pain.  There  is  strong  evidence  that  not  only  the  nerve- 
endings,  but  even  the  whole  of  the  nerve-tracts  of  which 
they  are  the  endings,  are  specialized  for  the  purpose  of  re- 
ceiving thermal  impressions.  These  impressions,  when 
received,  are  not  absolute,  but  relative  to  the  temperature  of 
the  part  receiving  them — the  greater  the  difference  of  tem- 
perature between  the  part  and  the  object  touching  it,  the 
greater  being  the  impression.      Moreover,  the  greater  the 


til 


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i  1 . 

96 


MENTAL  EVO1.UTION  IN  ANIMALS. 


extent  of  the  receiving  surface,  the  greater  is  the  impression ; 
so  that  if  the  whole  hand  be  immersed  in  water  at  102°,  the 
temperature  of  the  water  will  be  erroneously  judged  to  be 
higher  than  that  of  another  body  of  water  at  104°  the  tem- 
perature of  which  is  simultaneously  estimated  by  a  single 
finger  of  the  other  hand ;  and,  similarly,  smaller  differences 
of  temperature  can  be  appreciated  by  the  whole  hand 
than  by  a  single  finger.  According  to  Weber,  the  left  hand 
is  considerably  more  sensitive  to  temperature  than  the  right ; 
and  it  is  certain  that  different  parts  of  the  body  differ  greatly 
in  this  respect.  The  more  sudden  the  change  of  temperature, 
the  greater  is  the  sensory  effect.  We  have  no  means  of 
testing  the  truth  of  any  of  these  statements  with  reference 
to  any  of  the  Invertebrata,  or  even  with  reference  to  the 
cold-blooded  Vertebrata;  but  we  can  scarcely  doubt  that 
they  apply  in  a  general  way  to  all  the  warm-blooded.  The 
facts  certainly  show  an  elaborate  provision  for  appreciating 
local  changes  of  temperature  occurring  upon  thia  and  that 
part  of  the  external  surface  (the  general,  comfort  or  discom- 
fort arising  from  the  body  being  kept  at  a  normal  tempera- 
ture or  not  is  another  matter,  and  one  with  which  the  special 
mechanism  we  are  considering  is  not  concerned) ;  and  there- 
fore we  have  to  contemplate  the  probable  cause  of  its  origin 
and  development. 

At  first  sight  we  appear  to  encounter  a  difficulty  which  I 
wonder  never  to  have  seen  adduced  by  opponents  of  evolu- 
tion. For  in  nature  the  only  differences  of  temperature 
which  normally  occur  in  objects  with  which  animals  Lave 
any  opportunity  of  coming  into  contact,  are  those  between 
ice  and  objects  heated  by  a  tropical  sun  ;  and  no  one  animal 
ever  has  the  opportunity  of  experiencing  changes  of  tem- 
perature extending  through  anything  like  so  great  a  range ; 
for  in  the  arctic  regions  there  is  no  tropical  sun,  in  the 
tropics  there  is  no  ice,  and  in  the  temperate  zones  the  solar 
heat  is  moderate.  Of  course  since  the  introduction  of  fire  by 
man,  the  sense  of  temperature  has  become  of  much  use  to 
sundry  species  of  animals  for  the  examination  of  food,  &c.,  and 
in  this  connection  is  of  almost  indispensable  service  to  man 
himself ;  but,  looking  to  the  antecedents  of  these  animals 
and  also  to  the  antecedents  of  man,  it  may  at  first  sight 
seem  remarkable  that  such  an  elaborate  provision  should 
have  been  developed,  and,  as  I  have  said,  I  wonder  that  no 


1 


'i 


SENSATION. 


97 


opponent  of  evolution  has  pointed  to  the  fact.      For  it  might 
be  argued  that  here  we  have  a  complicated  piece  of  special 
organic  machinery  constructed  in  obvious  anticipation  of  the 
advent  of  cookery  and  warm  baths.     But  I  think  the  matter 
may  be  explained  on  evolutionary  principles,  if  we  remember 
that  the  only  use  of  a  sense  of  temperature  is  not  that  of 
exammmg  food.      Vie  know  that  differences  of  temperature 
on  the  surface  of  the  body  (whether  local  or  general)  greatly 
modify  the  conditions  of  the  circulation  in  the  part  or  parts 
affected,  and  therefore  it  must  always  have  been  of  use  for 
animals  to  be  provided  with  a  sensory  apparatus  upon  the 
surface  of  their  bodies  to  give  them  immediate  information 
of  such  differences.      Its  development  along  special  lines  (so 
that  some  parts  of  the  body  should  be  more  sensitive  to 
changes  of  temperature  than  other  parts)  is   easily  to  be 
explained  by  the  effects  of  habit  or  use.     Thus,  for  example, 
the  fact  that  the  lips  of  man,  although  provided  with  a  skin 
so  dehcate  and  so  sensitive  to  tactile  impressions,  are  never- 
theless able  to  endure  a  sudden  rise  of  temperature  which 
would  be  painful  to  the  skin  of  the  face,  must  be  taken  to 
mean  that  habit  has  adapted  the  nerves  in  the  lips  to  with- 
stand a  sudden  rise  of  temperature— and  this  certainly  within 
the  period  since  the  invention  of  cookery. 
^     Mr.  Grant  Allen  takes  a  more  general  vifew  of  this  sub- 
ject, and  says:  "To  an  animal,  cold  is  death,  and  warmth  is 
life.     Hence  it  is  not  ar.tonishing  that  animals  should  very 
early  have  developed  a  sense  which  informed    them    of 
changes  of  temperature  taking  place  in  their  vicinity ;   and 
that  this  sense  should  have  been  equally  diffused  over  the 

whole  organism As  soon  as  moving  creatures 

?J^?*^°m?^^  ^^  ^"'  ^^^y  probably  began  to  feel  hea.  and 
cold.  *  _  The  truth  of  such  a  general  statement  of  this  must 
be  obvious,  and  the  step  between  a  sense  of  temperature 
equally  diffused  over  the  whole  oiganism,  and  the  specializa- 
tion of  superficial  nerve-endings  to  minister  to  this  sense 
alone,  is  not  a  large  step.  Moreover,  the  step  between  this 
and  the  development  of  a  rudimentary  visual  organ  is  like- 
wise not  a  large  one.  For  the  deposition  of  dark-coloured 
pigment  m  particularly  exposed  parts  of  the  skin  must  have 
been  of  benefit  to  animals  by  enabling  (in  virtue  of  the 
increased  absorption  of  heat  thus  secured)  the  nerve-endinga 

*  Colour  Sense,  p.  13. 


I 
1 


m' 


!    M 


iMi  ■' 


■!i;;i 


!  I- 


A\ 


li: 


lill; 


!  I  ■ 


98 


MENTAL  EVOLUTION  IN  ANIMALS. 


in  those  parts  to  be  more  sensitive  to  changes  of  temperature. 
But  the  deposition  of  pigment  in  such  localities  constitutes  a 
favouring  condition  to  the  origination  of  an  eye,  or  of  an 
organ  whose  sense  of  temperature  becomes  sufficiently 
developed  to  enable  it  to  begin  to  distinguish  between  light 
and  darkness.  Thus,  as  Professor  Hfeckel  eloquently  re- 
marks :  "  The  ordinary  nerves  of  the  skin  which  pass  to  these 
dark  pigment-cells  of  the  integument,  have  already  trodden 
the  first  steps  of  that  magnificent  march,  at  the  end  of  which 
they  have  attained  to  the  highest  development  of  tl  e  nerves 
of  sensation — the  optic  nerves." 

Turning  next  to  the  sense  of  Colour,  it  appears  from  the 
experiments  of  Engelmann  already  alluded  to,  that  colour- 
sense  of  a  kind  occurs  as  low  down  in  the  zoological  scale  as 
the  protoplasmic  and  unicellular  organisms,  inasmuch  as 
particular  species  showed  particulpr  preferences  for  certain 
rays  of  the  spectrum.  But  as  in  these  organisms  there  are 
no  organs  of  special  sense,  and  probably  no  beginnings  of 
consciousness,  I  do  not  think  that  any  true  analogy  can  be 
drawn  between  these  cases  and  those  in  which  there  is  a  true 
sensation  of  colour.  Nor  have  we  any  evidence  of  such  a 
true  sensation  till  we  arrive  at  the  Crustacea.  Here  we 
have  proof,  furnished  by  the  direct  experiments  of  Sir  John 
Lubbock,  that  Daphnia  pulex  prefers  certain  rays  of  the 
spectrum  to  others,*  and  the  Chameleon  Shrimp  (Mysis  chcu- 
meleo)  is  known  to  change  its  colour  in  imitation  of  the 
surface  on  which  it  reposes,  provided  that  it  is  not  blinded 
or  otherwise  prevented  from  seeing  that  surface.  Precisely 
analogous  facts  occur  among  the  Cephalopoda  {e.g.,  octopus), 
Batrachia  {e.g..  Common  Frog),  Reptilia  {e.g.,  Cam'eleon),  and 
Pisces  {e.g.,  Flounder) ;  in  all  these  cases,  if  the  animals  are 
blinded,  the  effects  no  longer  occur.  Moreover,  Pouchet 
found  that  in  the  Pleuronectidee  the  mechanism  whereby 
these  imitative  changes  of  colour  are  produced  is  bilaterally 
disposed,  so  that  if  only  one  eye  of  the  animal  is  stimulated 
by  coloured  light,  only  one  side  of  the  animal  changes  colour. 
M.  Fredericq  afterwards  found  the  same  thing  to  be  true  of 
the  Octopus,  and  in  conjunction  with  Professors   Burdon- 

•  Journ.  Linn.  Soc,  1881.  These  observations  have  been  adversely  criti- 
cized bj  Merejkowsky  (Comptes  Sendus,  xciii,  pp.  160-1),  but  his  criticisms 
have  been  fully  met  by  further  experiments  recently  published  by  Sir  John 
(Journ.  Linn.  Soc,  1883). 


■  ^'  ' 

s 

■    i'r            1 

!•:               ! 

>■  iy 

' 

i  I 

; 

, 

1  ■►  _ . 

SENSATION. 


99 


Sanderson,  Cossar  Ewart,  and  Mr.  W.  D.  Scott,  I  have 
corroborated  M.  Fredericq's  observations  by  a  number  of 
experiments ;  stimulation  of  one  eye  alone  by  means  of  light 
produces  immediate  unilateral  flushing  of  the  whole  of  the 
same  side  of  body,  but  no  change  of  colour  beyond  the  median 
line. 

As  further  proof  that  a  well-developed  sense  of  colour 
occurs  in  some  of  the  Articulata,  I  may  allude  to  the  experi- 
ments of  Sir  John  Lubbock  on  the  Hymenoptera ;  but  as 
these  have  been  already  twice  published  in  the  International 
Scientific  Series,*  I  need  not  here  wait  to  recapitulate  them, 
and  shall  therefore  only  remark  that  it  is  without  any  rea- 
sonable question  to  the  presence  of  this  sense  in  insects  that 
we  owe  the  beauty  both  of  floral  and  of  insect  coloration. 
Again,  as  further  proof  that  a  well-developed  sense  of  colour 
occurs  in  Fish,  I  may  remark  that  the  elaborate  care  with 
which  anglers  dress  their  flies,  and  select  this  and  that  com- 
bination of  tints  for  this  and  that  locality,  time  of  day,  &e., 
shows  that  those  who  are  practically  acquainted  with  the 
habits  of  trout,  salmon,  and  other  fresh-water  fish,  regard  the 
presence  of  a  colour-sense  in  them  as  axiomatic.  And,  with 
reference  to  the  sea-water  fish  in  general,  we  have  the  highly 
competent  opinion  of  Professor  H.  N.  Moseley  to  the  effect 
that  the  great  majority  of  the  colours  of  marine  animals 
have  been  acquired  either  for  the  protection  or  the  allure- 
ment of  prey,  and  that  they  refer  particularly  to  the  eyes  of 
Fish,  and  also  to  those  of  Crustacea.! 

The  fact  that  a  sense  of  colour  occurs  in  Birds  is  unques- 
tionable, and  meets  with  its  most  general  proof  in  the  more 
or  less  conspicuous  coloration  of  the  fruits  on  which  they 
feed ;  for  as  in  the  analogous  case  of  conspicuously  coloured 
flowers  depending  on  insects  for  their  fertilization,  so  con- 
spicuously coloured  fruits  depend  for  the  dissemination  of 
their  seeds  upon  being  eaten  by  birds  or  mammals.  Again, 
I  have  already  mentioned  the  fact  that  nowhere  in  the 
animal  kingdom  does  the  protective  and  imitative  colouring 
of  animals  atlfain  to  such  nicety  as  it  does  where  the  eyes 
of  birds  are  concerned.  Lastly,  the  elaborate  coloration  of 
birds  themselves,  and  the  pleasure  which  some  species  take 
in  the  decoration  of  their  nests,  constitute  supplementary 

•  Viz.,  in  Ants,  Bees,  and  Wasps,  and  in  Animal  Intelligence. 

t  (Quarterly  Journ.  Micro,  Science,  New  Series,  vol.  xvii,  pp.  19-22, 


i::;'H| 


I.  I 


wm 


;r'  1; 


T  :-!> 


I 


M\ 


100 


MENTAL  EVOLUTION  IN  ANIMALS. 


proof  of  the  high  development  to  which  the  colour-sense  has 
attained  m  this  class. 

All  the  remarks  just  made  with  reference  to  Birds,  apply 
likewise  though  not  perhaps  in  quite  so  high  a  degree,  to 
Mammals,  considered  as  a  class.  And  here  it  becomes  need- 
tul  to  consider  the  speculation  of  Dr.  Magnus  and  Mr.  Glad- 
stone, that  the  colour-sense  of  man  has  undergone  a  great 
improvement  within  the  last  two  thousand  yeaV  inasmuch 
as  before  that  time  mankind  are  supposed  by  this  specula- 
tion to  have  perceived  only  the  lower  colours  of  the  spec- 

i,r°5'."'.r,'-T"^^'  ^""^  yellow,  and  to  have  been  colour- 
blind  to  the  liigher,or  green,  blue,  and  violet.  Professor  Hackel 
lends  his  support  to  this  speculation ;  but  to  me  it  seems  a 
highly  improbable  one,  and  this  for  the  following  reasons 

In  the  first  place   the  speculation  is  based  merely  on 
etymological  grounds,  which  in  a  matter  of  this  kind  are 
exceedingly  unsafe.    For  the  absence  in  a  language  of  words 
denoting  particular  colours  is,  at  best,  but  negative  evidence 
that  the  men  who  spoke  the  language  were  blind  to  those 
colours;  the  absence  of  such  words  may  quite  as  weU  be  due 
to  the  imperfection  of  language  as  to  the  imperfection  of  the 
visual  sense.  Thus,  for  instance.  Professor  Blackie  tells  us  that 
the  Highlanders  call  both  sky  and  grass  "gorm,"  and  are 
nevertheless  quite  able  to  discriminate  between  the  colours 
blue  and  green.     In  the  next  place,  it  is  antecedently  im- 
probable, upon  the  general  principles  of  evolution,  that  a 
considerable  change  in  the  visual  apparatus  of  man  should 
have  taken  place  within  so  short  a  period  as  the  speculation 
in  question  assigns— especially  in  view  of  the  fact  that  other 
Mammals    Birds,  and   even  some  of  the  Invertebrata  un- 
questionably distinguish  the  higher  as  well  as  the  lower 
colours  of  the  spectrum.     Lastly,  Mr.  Grant  Allen  has  taken 
the  trouble  to  enquire,  by  means  of  a  table  of  questions 
addressed  to  educated  Europeans  in  all  parts  of  the  world 
whether  any  of   the  savage  races  of  mankind  now  livin« 
display  any  inability  to  distinguish  between  the  colours  of 
the  spectrum,  and  the  answers  which  he  has  received  have 
been  uniformly  in  the  negative.*     I  think,  therefore,  we  may 
sately  dismiss  the  speculation  of  Dr.  Magnus  and  Mr.  Glad- 
stone as  opposed  to  aU  the  evidence  which  is  at  once  trust- 
worthy and  available.     But  in  saying  this  I  do  not  intend  to 

•  Colour-sense,  Chapier  X. 


1 


SENSATION. 


101 


dispute  the  probability,  which  indeed  amounts  almost  to  a 
certainty,  that  as  civilization  advances  and  the  fine  arts 
become  developed,  the  colour-sense  undergoes  a  progressive 
improvement  in  its  power  of  distinguishing  between  fine 
shades,  and  also  m  its  power  of  ministering  to  a  more  and 
more  evolved  condition  of  aesthetic  feeling.  And  this  I 
heheve  is  the  true  explanation  of  the  class  of  facts  aUuded  to 
by  Professor  H^ckel  as  proof  of  the  speculation  which  I  have 
now  discarded-the  fact,  namely,  that  "nowadays  we  see  in 
the  surviving  savage  races  a  crudity  as  to  their  sense  of 
colour  .  .  Our  little  ones,  also,  like  the  savages 
love  assemblages  of  glaring  hues  which  grate  upon  us,  and 
susceptibility  to  the  harmony  of  delicate  shades  of  colour  is 
the  latest  product  of  aesthetic  education  " 

Professor  Preyer  has  published  within  the  last  year  or  two 
avery  interesting  theory  touching  the  origin  and  development 
ot  the  colour  sense,  and  as  it  has  not,  to  my  knowled^^e  been 
no  iced  in  any  English  publication,  I  shall  here  state  the  main 

Ki  u^  5®'''?  ''  *^^*  *^^  colour-sense  is  a  special  and 

highly-exalted  development  of  the  sense  of  temperature    To 
sustain  this  theory  Professor  Preyer  first  compares  the  sensi- 
bihty  of  the  skm  to  temperature  with  that  of  the  retina  to 
light,   and  points  out   that  the  analogy  has  already  been 
recognized  by  artists,  who  speak  of  colours  as  "  warm  "  and 
cold.    _     The  warm  colours  arouse  sensations  of  a  character 
antagonistic  to  those  which  are  aroused  by  the  cold  colours 
m  just  the  same  way  as  the  hot  and  cold  sensations  of  skin- 
temperature  are  antagonistic ;  and  the  more  this  analosy  is 
pursued,  the  closer  is  the  agreement  found  to  be."    Therefore 
the  suggestion  arises,  "  that  the  sense  of  colour  has  been 
developed  out  of  the  sense  of  temperature,"  bespeaking  a 
high  refinement  of  functional  activity  which  has  its  struc- 
tural correlative  m  the  extremely  differentiated  and  delicately 
organized  expansion  of  nerve-endings  which  we  find  in  the 

AC  till  3(, 

A  further  analogy  is  that  of  contrasts.  A  finger  that  has 
been  warmed  or  coo  ed  retains  its  change  of  temperature  for 
some  time  after  it  has  ceased  to  be  warmed  or  cooled ;  and 
this  is  taken  to  correspond  with  the  phenomena  of  positive 
n  w  ir%''  .'''  sensation:  -  colour.  Moreover,  while  the 
after-effect  of  warming  or  cooling  a  portion  of  the  skin 
remains,  the  temperature-sense  of  that  portion  is  altered  in 


ri 


I:. 


B.j.  .        :         I 


■  H     ' ,  t| 


102 


MENTAL  EVOLUTION  IN  ANIMALS. 


I    : 


. ;-(! 


II I  u 


it- 


\  r 


Buch  wise  that,  if  it  has  been  cooled,  it  over-estimates  the 
temperature  of  any  object  it  may  touch,  and  vice  versd.  This 
is  taken  to  be  analogous  to  the  appearance  of  warm  colours 
in  the  eyes  when  closed  immediately  after  having  been 
exposed  to  intense  coM  colours,  and  vice  versd.  So,  too,  it  is 
with  simultaneous  contrasts.  It  is  well  known  that  if  a 
small  colourless  surface  is  enclosed  between  two  surfaces  of 
cold  or  warm  colours,  the  small  surface  will  appear  inversely 
coloured  warm  or  cold,  as  the  case  may  be ;  and  Professor 
Preyer  has  found  by  experiment,  that  if  a  small  portion  of  the 
skin  be  enclosed  by  cold  or  warm  surfaces  on  either  side,  the 
small  enclosed  area  will  feel  cool  if  the  neighbouring  parts 
are  heated,  and  vice  versd. 

After  showing  that  in  his  view  illumination  is  to  the 
sense  of  colour  what  contact  is  to  the  sense  of  temperature, 
and  pointing  out  several  subordinate  analogies  which  I  have 
no  space  to  mention,  Professor  Preyer  goes  on  to  remark  an 
important  fact  in  relation  to  his  theory,  viz.,  that  different 
parts  of  the  skin  manifest  in  their  estimations  of  tempera- 
ture great  differences  in  their  estimates  of  what  he  calls  the 
"  neutral  point,"  i.e.,  the  point  at  which  it  cannot  be  said  that 
a  body  is  felt  to  be  either  hot  or  cold.  The  retina,  then,  being 
supposed  to  be  merely  a  nerve-expansion  having  a  much 
higher  "  neutral  point "  in  the  appreciation  of  temperature 
(ethereal  vibrations)  than  has  any  nerve-expansion  of  the 
skin,  colour-blindness  is  explained  by  supposing  that  the 
retina  of  the  individual  so  affected  has  a  neutral  point  either 
above  or  below  the  normal.  "  An  over- warm  eye  must  be 
blind  to  yellow  and  blue ;  an  over  cool  one  must  be  blind  to 
red  and  green."  Total  colour-blindness,  which  is  a  physio- 
logical characteristic  among  certain  nocturnal  animals,  has  its 
parallel  in  the  pathological  condition  sometimes  met  with  in 
man,  of  a  total  absence  of  the  sense  of  temperature  without 
impairment  in  the  sense  of  touch. 

Lastly,  it  is  observed  that  the  first  condition  to  the 
validity  of  any  physiological  hypothesis  is  that  it  should 
accord  with  morphological  fact.  But  this  is  not  the  case  with 
the  theory  of  Young  and  Helmholtz,  which  ascribes  the 
colour-sense  to  the  functions  of  three  retinal  elements ;  for  it 
has  been  proved  that  the  number  of  fibres  in  the  optic  nerve 
immediately  before  it  enters  the  retina  is  much  smxUer  than 
the  number  of  rods  and  cones  in  the  retina. 


i 


^ 


SENSATION. 


108 


In  my  opinion  this  theory,  in  its  main  outlines,  seems  a 
probable,  as  it  certainly  is  a  plausible  one.  I  do  not,  indeed 
quite  understand  why,  in  accordance  with  the  theory  the 
'; neutral  point"  of  the  colour-blind  should  not  merely  be 
tound  to  be  shifted  to  another  part  of  the  spectrum,  nor  am  I 
quite  clear  about  the  explanation  of  the  fact  that  the  warm 
colours  are  those  having  the  lowest  and  not  the  highest  order 
of  vibrations,  as  analogy  would  lead  us  to  expect.  But  the 
theory  has  the  merit  of  being  antecedently  probable,  when  we 
remember  that  in  all  likelihood  the  visual  ^ense  arose  by  the 
progressive  elaboration  of  nerve-endings  in  particular  parts  of 
the  skin,  which  before  their  special  elaboration  presumably 
ministered  to  the  senses  of  touch  and  temperature. 

And  this  remark  leads  me  to  the  last  topic  that  I  have  to 
dwell  upon  in  the  present  chapter.     I  refer  to  the  body  of 
morphological  evidence  which  we  now  possess,  showing  that 
all  the  organs  of  special  sense  have  had  their  origin  in  fecial 
elaborations  of  these  nerves  of   the  integument.    For  the 
uniform  result  of  histological  and  embryological  investigation 
is  to  show  that  all  organs  of  special  sense,  wherever  they 
occur  and  whatever  degree  of  elaboration  they  present  in  the 
adult  animal,  are  fundamentally  alike  in  that  their  receptive 
surfaces  are  composed  of  more  or  less  modified  epithelium 
cells  which  originally  constituted  part  of  the  external  layer 
of  the  animal.     Thus,  the  origin  of  the  olfactory  membrane 
m  the  embryo  of  the  Vertebrata  is  found  to  consist  in  a  pittincr 
of  the  skin  of  the  fore  part  of  the  head— the  pits,  therefore'J 
being  lined  by  the  general  layer  of  epidermic  cells.     The 
subsequent  growth  of    the  surrounding  parts  of  the  face 
eventually  brings  this  lining  to  occupy  the  position  which  it 
does  in  the  hollow  parts  of  the  nose.     Similarly,  the  organs 
of  hearing  first  begin  as  a  pair  of  pits  on  the  side  parts  of  the 
head,  situated  somewhat  far  back,  and  likewise  lined  by  the 
cells  of  the  general  integument.     These  pits  rapidly  deepen, 
so  that  their  lining  is  pinched  off  or  separated  from  the 
general  integument  of  which  it  originally  formed  a  part.   The 
deep  pit  then  becomes  a  closed  sac,  and  the  adjacent  tissues 
becoming  first  cartilaginous  and  then  osseous,  this  sac  is 
enclosed  well  within  the  skull  by  bony  walls.    While  its 
structure  is  undergoing  further  anatomical  and  histological 
changes,  the  drum,  the  chain  of  ear-bones,  and  the  external 
ear  are  being  formed,  and  thus  eventually  the  auditory  organ 


if  rt-ti  Yi 


104 


MENTAL  EVOLUTION  IN  ANIMALS. 


•! 


is  completed.    In  the  case  of  the  eye,  again,  the  earliest  sign 
of  commencement  consists  in  a  similar  pitting  of  the  general 
integument,  but  the  lining  of  this  pit  is  not  destined,  as  in 
the  previous  cases,  to  become  the  receptive  surface  of  the 
sensory  impressions.     For,  after  it  has  deepened  considerably 
it  undergoes  sundry  changes  which  result  in  its  forming  the 
cornea,  aqueous  humour,  and    crystalline  lens;   while  the 
retina  arises  as  an  offshoot  from  the  brain  in  the  form  of  a 
sac  growing,  as  it  were,  upon  a  slender  stalk  towards  the 
crystalline  lens.    At  first  the  anterior  surface  of  this  sac  is 
convex,  but  the  posterior  part  afterwards  becomes  pushed 
into  the  cavity  of  the  sac;   so  that  the  anterior  surface 
eventually  becomes  strongly  concave.     Therefore  the  sac  is 
now,  as  Professor  Huxley  graphically  describes  it,    "like  a 
double  night-cap,  ready  for  the  head,  but  the  place  which  the 
head  would  occupy  is  taken  by  the  vitreous  humour,  while 
the  layer  of  night-cap  next  it  becomes  the  retina."    Thus  the 
rods  and  cones  of  the  retina  are  not  developed  immediately 
out  of  the  epidermic  cells  of  the  integument ;  but  inasmuch  as 
the  brain  is  itself  begun  as  an  infolding  of  the  epidermic  layer, 
the  rods  and  cones  of  the  retina  are  ultimately  derived  from 
those  epidermic  cells.     Or,  again  to  quote  Professor  Huxley, 
"the  rods  and  cones  of  the   vertebrate  eye  are  modified 
epidermal  cells,  as  much  as  the  crystalline  cones  of  the  insect 
or  crustacean  eye  are."*     Therefore,  in  the  words  of  Professor 
Hseckel,  "  the  general  conclusion  has  been  reached  that  in 
man,  and  in  all  other  animals,  the  sense-organs  as  a  whole 
arise  in  essentially  the  same  way,  viz.,  as  parts  of  the  external 
integument  or  epidermis.    The  external  integument  is  the 
original  general  sense-organ.      Gradually  the  higher  sense- 
organs  detach  themselves  from  this  their  primal  condition, 
whilst  they  withdraw  more  or  less  completely  into  the  pro- 
tecting parts  of  the  body.    Nevertheless  in  many  [inverte- 
brate] animals,  even   at  the  present  hour,  they  lie  in  the 
integument,  as  e.g.,  in  the  Vermes." 

I  have  entered  thus  fully  into  this  general  fact,  because 
it  is  of  importance,  not  only  to  the  theory  of  evolution,  but 
also  to  the  philosophy  of  sensation,  to  know  from  such  direct 
historical  sources  that  all  the  special  senses  are  differentiations 
of  the  general  sense  of  touch. 

•  Science  and  Culture,  &.C.,  p.  271t 


it 


'     i 


3 


PLEASURES  AND  PAINS. 


105 


''■  11 

mi 


CHAPTER  VIII. 


.!  ■ 


Pleasures  and  Pains,  Memory,  and  Association  of  Idea^ 

In  the  diagram  I  have  represented  Pleasures  and  Pains  as 
occupying  in  their  first  origin  a  level  not  far  removed  from 
that  at  which  Sensation  takes  its  rise.  I  have  also  repre- 
sented a  short  interval  hetween  Sensation  and  the  origin  of 
Perception,  which  is  filled  up  in  the  lateral  column  by 
Memory  and  Primary  Instincts.  Therefore,  before  we  pass 
on  to  consider  the  rise  of  Perception  out  of  Sensation,  I  shall 
devote  a  chapter  to  a  consideration  of  Pleasures  and  Pains, 
Memory,  and  Association  of  Ideas. 

Pleasures  and  Pains. 

On  this  topic  I  have  little  to  add  to  the  treatment  which 
it  has  received  at  the  hands  of  Mr.  Herbert  Spencer,  and  of 
his  disciple,  Mr.  Grant  Allen.*  Pains,  as  Mr.  Spencer  points 
out,  may  be  due  to  the  want  of  action  ("  craving  "),  or  to  an 
excess  of  action.  These  two  classes  correspond  largely, 
though  not  entirely,  with  the  division  of  pains  into  massive 
and  acute,  which  is  formulated  by  Professor  Bain.  It  also 
indicates  the  doctrine  of  Sir  W.  Hamilton  and  others,  that 
Pain  is  due  to  excessive  stimulation.  But  it  is  important  to 
observe  that  the  statement  of  Mr.  Spencer,  while  "  recognizing 
at  one  extreme  the  positive  pain  of  excessive  actions,"  recog- 
nizes also  "  at  the  other  extreme  the  negative  pains  of  in- 
actions ;  the  implication  is  that  Pleasures  accompany  actions 
lying  between  these  extremes." 

Mr.  Grano  Allen  in  the  course  of  his  able  exposition  of 
this  subject,  shows  by  many  examples  that  "the  Acute 
Pains,  as  a  class,  arise    from  the  action  of    surrounding 

*  See  Principles  of  Pnychology  and  Physiological  Esthetics,  in  both 
cases  the  chapter  on  "  Pleasui-es  and  Pains." 


I  II 


M 


106 


MENTAL  EVOLUTION  IN  ANIMALS. 


yi:^] 


destructive  agencies;   the  Massive  Pdns    as  a  class   from 

'^aSpaTnfwh  "  "^^^^^"^    ^'^^'    ^^o   'Z 
Ar.,f!  PI      »     '  .?^''  P,""'^^^  ^°  ^n  extreme,  merge  into  the 

fheriSr  hi?  '^''  "  '?'  '"^^  ^^^^^^^  ^^^  r^^^^r  indefinite  in 
their  limits,  heing  simply  a  convenient  working  distinction 

ZL"^'ZV:lT':-    ^^"^^  ^^^'^^^^-«  ^hat  PaS'of  both 
Classes    are  the  subjective  concomitants  of  an  actual  disnm 

tion  or  disruptive  tendency  in  some  one  (or  moi^)  ofthe 

cett  Sr;f'  \'T'  ^'  -PP^-dS^afferen 
cereDro-spinal  nems  m  unbroken  connexion  with  the  brain" 
deferring  the  reader  to  Mr.  Allen's  own  essay  for  all  mat  ers 
of  detail  and  criticism,  I  shall  merely  say  that  in  my  ZinZ 

al  \ZeTTF^'  '^f  "'^'  this  Vula  as  ap'pLXe  to 
ail  cases  ot  lam.  His  view  concerning  the  phvsiolocrv  of 
Pleasure  is  substantially  the  same  as  that  of  M^r  Ker 

cte  %r  vti^"'  l  f  ^?"^^^^^^  "^'^  extended  a7dp. 
cise.     1  his  view  is  that  Pleasure  is  "the  concomitint  of  a 

normal  amount  of  activity  in  any  portion  or  t^  wTole  of  the 

"XToirPpr"''^  with  the'important  aJ.S.ftha 
the  strongest  Pleasures  result  from  the  stimulation  of  the 
largest  nervous  organs,  where  activities  are  most  intermittent  " 

timber  o?  r^'fi^'  ^''''T  \'  "'^  ^^^  direVt  S  ol'the 
number  of  nerve-fibres  involved,  and  in  the  inverse  ratio  of 

the  natural  frequency  of  excitation."    Hence  "we  ^e  wherein 

Sflill  n?y^  ^  'T'  ^f'  ^^  ^'  «^^^<^ly  antitheticaUo  tl  e 

fan    Vl     ""'i^r^  "'  *^'^  °^J^^^^^«  antecedents  similarly 

s^v  ofZT-^  ^p''"'t  '^°  '^^^^"^  °^  ^«^«r  attain  the  intend 
sity  of  Massive  Pam,  because  the  organism  can  be  brought 

itTffil'nr'r^P"^^'  of  innutrition  or  exhaus  ionX 
Its  efficient  working  cannot  be  raised  very  high  above  the 
average.  Similarly  any  special  organ  or  plexus  of  nerves  en 
undergo  any  amount  of  violent  disruption  orwastbJaway 
giving  rise  to  extremely  Acute  Pains ;  but  organs  a^reveiT 
seldom  so  highly  nurtured  and  so  long  deprived  of  thek 
appropriate  stimulant  as  to  give  rise  to  ve'ry  Ac^Ie  Pleasure  » 
poin^rT^Tt  f^^^^^^H^on  do  theL  generaStions 
point  ?  They  clearly  pomt  to  the  conclusion,  Shich  I  do  not 
thmk  IS  open  to  any  one  valid  exception,  th^t  Pains  are  Sie 

cltantcf.T^^'^r'''^'"  Pleasures  are  the^ubjective  con- 
ore^,  t^  '"'^  organic  changes  as  are  beneficial  to  the 
orgamsm-or,  we  must  add,  to  the  species.     The  more  this 


PLEASURES  AND  PAINS. 


107 


doctrine  is  pursued  m  detail,  the  more  unquestionable  does 
Its  truth  become.     Thus  there  is  to  be  perceived,  not  merely 
a  general  qualitative,  but  also  a  roughly  quantitative  relation 
between  the  amount  of  pain  and  the  degree  of  hnrtfulness  as 
well  as  between  the  amount  of  pleasure  and  the  degree  of 
wMcsomeness.^^     As  Mr.  Allen  observes,  "  nothing  can  more 
thoroughly  mihtate  against  the  efficiency  of  the  mechanism 
than  the  loss  of  one  of  its  component  parts:  and  we  find 
accordingly  that  to  deprive  the  body  of  any  one  of  its  mem- 
Ders  is  paintul  in  a  degree  roughly  proportionate  to  the 
general  value  of  such  member  to  the  organism  as  a  whole, 
lake,  for  example,  the  relative  painfulness  of  severing  from 
the  body  a  leg,  an  arm,  an  eye,  a  finger-nail,  a  hair,  or  Apiece 
t         \.    Snmlarly  with  Pleasures,  the  least  pleasurable  are 
those  attending  activities  of  the  organism  which  are  least 
important  for  its  welfare  (or  for  that  of  its  species),  while 
the  most  pleasurable  are  those  which  attend  the  satisfaction 
of  hunger,  thirst,  and  sexual  desire-especially  if,  in  terms  of 
Mr.   Aliens  formula,   the  needs  to   which   these  cravings 
minister  have  been  long  unsatisfied,  so  that  the  organism  Is 
either  in  danger  of  enfeeblement  and  death,  or  in  the  most 
lit  condition  lor  propagating  its  kind.     Pleasures  of  the  intel- 
lectual kind,  although  subservient  to  the  same  general  laws 
ot  nutrition  and  exhaustion,  have  referenee  to  such  complex 
nervous  states  involving  mental  prevision  of  future  contin- 
gencies, &c.,  that  for  the  purposes  of  clear  analysis  they  had 
best  be  here  disregarded.  ^      "■ 

The  superficial  or  apparent  objection  to  the  doctrine  we 
are  considering  which  arises  from  the  fact  that  feelinrrg  of 
Pleasure  and  Pam  are  not  infallible  indices  of  what  is  respec- 
tively beneficial  or  injurious  to  the  organism,  is  easily  met  by 
the  consideration  that  in  all  such  exceptional  cases  it  is  not 
the  doctrine  but  its  application  which  is  at  fault      Thus 
again  to  quote  Mr.  Allen,  who  in  my  opinion  has  given  in 
brief  compass  the  best  analysis  of  the  philosophy  of  Pleasure 
and  Pam  that  has  hitherto  appeared,  "every  act,  so  long  as 
It  IS  pleasurable,  is  in  so  far  a  healthy  and  useful  one  •  and 
conversely,  so  long  as  it  is  painful,  a  morbid  and  destructive 
^"^■j    .  J  ,  ^^"^^y  ^^^^  ^^  ^^^®  proleptic  employment  of  the 
words    deleterious '  and  '  useful?^    To  put  it  in  a  simple  form. 


:"■! 


:'!    f 


1  : 


r  ' ' 


i    ■1 


m 


« j  j  i 

.111 


108 


t|!|i 


1 

■  , 

1 

■ 

di- 

■ 

f  ^ 

1 

1 

l:^ 

; 

m.1 

■ 

MENTAL  EVOLUTION  IN  ANIMALS. 


tlie  nervous  system  is  not  prophetic.  It  informs  us  of  what 
is  its  actual  state  at  the  moment,  not  what  the  after-effects  of 
that  state  will  be.  If  we  take  sugar  of  lead,  we  receive  at 
first  a  pleasant  sensation  of  sweetness,  because  the  immediate 
effect  upon  the  nerves  of  taste  is  that  of  a  healthy  stimu- 
lation. Later  on,  when  the  poison  begins  to  work,  we  are 
conscious  of  a  painful  sensation  of  griping,  because  the  nerves 
of  the  intestines  are  then  being  actually  disintegrated  by  the 
direct  or  indirect  action  of  the  irritant." 

Now  if  the  doctrine  before  us  is  found  to  apply  generally 
to  all  cases  of  Pleasure  and  of  Pain,  the  implication  is  suffi- 
ciently apparent;  Pleasures  and  Pains  must  have  been 
evolved  as  the  subjective  accompaniment  of  processes  which 
are  respectively  beneficial  or  injurious  to  the  organism,  and 
so  evolved  for  the  purpose  or  to  the  end  that  the  organism 
should  seek  the  one  and  shun  the  other.  Or,  to  quote 
Mr.  Spencer,  "  if  we  substitute  for  the  word  Pleasure  the 
equivalent  phrase — a  feeling  which  we  seek  to  bring  into 
consciousness  and  retain  there,  and  if  we  substitute  for  the 
word  Pain  the  equivalent  phrase — a  feeling  which  we  seek  to 
get  out  of  consciousness  and  to  keep  out;  we  see  at  once 
that,  if  the  states  of  consciousness  which  a  creature  endeavours 
to  maintain  are  the  correlatives  of  injurious  actions,  and  if 
the  states  of  consciousness  which  it  endeavours  to  expel  are 
the  correlatives  of  beneficial  actions,  it  must  quickly  disappear 
through  persistence  in  the  injurious  and  avoidance  of  the 
beneficial.  In  other  words,  those  races  of  beings  only  can 
have  survived  in  which,  on  the  average,  agreeable  or  desired 
feelings  went  along  with  activities  conducive  to  the  mainten- 
ance of  life,  while  disagreeable  and  habitually-avoided  feelings 
went  along  with  activities  directly  or  indirectly  destructive  of 
life,  and  there  must  ever  have  been,  other  things  equal,  the 
most  numerous  and  long-continued  survivals  among  races  ^'n 
which  these  adjustments  of  feelings  to  actions  were  the  best, 
tending  ever  to  bring  about  perfect  adjustments. 

"  If  we  except  the  human  race  and  some  of  the  highest 
allied  races,  in  which  foresight  of  distant  consequences  intro- 
duces a  complicating  element,  it  is  undeniable  that  every 
animal  habitually  persists  in  each  act  which  gives  pleasure, 
80  long  as  it  do'^A  so,  and  desists  from  each  act  which  gives 
pain.  It  is  in  ipife^t  that,  for  creatures  of  low  intelligence, 
there  caa  be  u-o  c 


aer  guidance." 


PLEASURES  AND  TAINa 


109 


Thus,  then,  wo  see  that  the  affixing  of  painful  or  disncree- 
able  states  of  consciousness  to  deleterious  changes  of  the 
organism,  and  the  reverse  states  to  reverse  changes,  has  been 
a  necessary  function  of  the  survival  of  the  fittest.  We  may 
further  see  that  in  bringing  about  this  adjustment  or  corre- 
spondence, the  zoological  principle  of  the  survival  of  the 
fittest  must  have  been  largely  assisted  by  the  physiological 
prmciple  that  Pleasure  tends  to  accompany  the  normal 
activity  of  an  organ  and  Pain  to  accompany  its  abnormal. 
For  as  organs  are  invariably  of  use  to  the  organism,  their 
normal  activity  must  always  be  beneficial  to  it;  while,  con- 
versely, their  abnormal  activity,  tending  to  cause  or  'beincf 
caused  by  their  own  disintegration,  must  always  be  harmful 
to  the  organism.  Survival  of  the  fittest  is  thus  provided 
with  a  ready-foi-med  condition  or  tendency  of  psycho-physio- 
logy on  which  to  work— a  tendency  which  survival  of  the 
fittest  may  itself  in  earlier  times  have  beer  instrumental 
m  producing ;  but  which,  in  any  case,  when  once  established 
must  greatly  assist  survival  of  the  fittest  in  apportioning  the 
a,ppropriate  state  of  consciousness  to  any  particular  organic 
process.  ° 

Another  principle  of  pyscho-physiology  must  likewise 
have  greatly  assisted  natural  selection  in  its  execution  of 
this  work.  This  principle  is  that  which  obtains  in  so-called 
acquired  tastes  and  distastes.  Thus,  as  Mr.  Spencer  observes, 
•'  Pleasures  and  Pains  may  be  acquired—may  be,  as  it  were' 
superimposed  on  certain  feelings  which  did  not  originally 
yield  them.  Smokers,  snuff-takers,  and  those  who  chew 
tobacco,  furnish  familiar  instances  of  the  way  in  which  long 
persistence  in  a  sensation  not  originally  pleasurable,  makes  it 
pleasurable— the  sensation  itself  remaining  unchanged.  The 
like  happens  with  various  foods  and  drinks,  which,  at  first 
distasteful,  are  afterwards  relished  if  frequently  taken 
Common  sayings  about  the  effects  of  habit  imply  recognition 
of  this  truth  as  holding  with  feelings  of  other  orders.  That 
acute  pain  can  be  superinduced  on  feelings  originally  agree- 
able or  indifferent,  we  have  no  proof.  But  we  have  proof 
that  the  state  of  consciousness  called  disgust  may  be  made 
inseparable  from  a  feeling  that  once  was  pleasurable :"  so 
that  even  in  the  life-time  of  the  individual  the  states  of 
consciousness  as  pleasurable  or  painful  may  reverse  their 
character  with  reference  to  the  same  organic  changes  or  sen- 


li'-ll 


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110 


MENTAL  BVOLUTION  IN  ANIMALS. 


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sations,  and  if  this  is  the  case  it  becomes  evident  with  what 
plastic  material  natural  selection  has  had  to  deal  in  moulding 
through  numberless  generations  the  form  of  consciousness 
which  best  fits,  with  refeience  to  the  welfare  of  the  organism, 
the  circumstances  of  stiumlation. 

Thus  we  may  well  believe  that  survival  of  the  fittest, 
acting  always  in  co-operation  with  these  principles  of  psycho- 
physioiog)-,  must  have  been  successful  in  accomplishing  the 
adjustments  here  assigned  to  its  agency— the  adjustments, 
that  is,  between  states  of  consciousness  as  agreeable  or  dis- 
agreeable and  circumstances  of  stimulation  as  beneficial  or 
deleterious.  And  thus  it  is  that  in  the  process  of  evolution 
organisms  "  have  gone  on  establishing  a  consensus  between 
the  various  organs  of  the  body,  so  that  at  last,  for  the  most 
part,  whatever  will  prove  deleterious  to  any  organ  proves 
deleterious  also  to  the  first  nerves  of  the  organism  which  it 
affects,"  and  therefore  disagreeable  to  ccnsciousness,  although 
of  course,  as  we  should  from  these  principles  expect,  this  is 
only  the  case  "when  the  deleterious  object  is  found  suffi- 
ciently often  in  the  environment  to  give  an  additional  point 
of  advantage  to  any  species  which  is  so  adapted  as  to 
discriminate  and  reject  it."* 

Thus  then,  it  seems  to  me,  we  have  aa  full  a  rationale  of 
Pleasures  and  Pains  as  we  can  expect  or  need  desire.  The 
only  difficulty  is  to  understand  the  connection  between  the 
objective  fact  of  injuriousness  or  the  reverse,  and  the  corre- 
sponding subjective  state  of  consciousness;  how  is  it  that 
injuriousness  or  the  reverse  comes  to  be,  as  it  were,  translated 
into  the  language  of  Pleasure  and  Pain.  But  this  is  only  the 
old  difficulty  of  understanding  the  connection  of  Mind  with 
Body,  and  has  no  reference  to  historical  psychology,  which  ' 
takes  the  fact  of  this  connection  as  granted.  Possibly,  how- 
ever— and  as  a  mere  matter  of  speculation,  the  possibility  is 
worth  stating— in  whatever  way  the  inconceivable  connection 
between  Body  and  Mind  came  to  be  established,  the  primary 
cause  of  its  establishment,  or  of  the  dawn  of  subjectivity, 

•  Grant  Allen,  loc.  cit.,  p.  27.  The  latter  consideration  disarms  any  criti- 
cism which  might  be  advanced  against  our  doctrine  on  account  of  the  agree- 
able tast*^  of  certain  poisons,  both  to  ourselves  and  to  the  lower  animals.  But 
it  is  astonishing  even  here  how  rapidly  the  appropriate  distaste  arises  after 
experience  of  the  injurious  effects :  witness  the  dislike  of  wine  which  may  fre- 
quently be  caused,  even  in  those  who  are  addicted  to  excess,  by  Burreptitiouslr 
mixing  it  with  nux-vomica. 


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MEMORY  AND  ASSOCIATION   OP  IDEAS. 


Ill 


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may  have  been  this  very  need  of  inducing  organisms  to  avoid 
the  deleterious,  and  to  seek  the  beneficial;  the  misan  d'e'tre 
of  Consciousness  may  have  been  that  of  supplying  the  con- 
dition to  the  feeling  of  Pleasure  and  Pain.    Be  tliis  as  it  mav 
however,  it  seems  certain,  as  a  matter  of  observable  fact,  that 
the  association  of  Pleasure  and  Pain  with  organic  states  and 
processes  which  are  respectively  beneficial  and  deleterious  to 
the  organism,  is  the  most  important  function  of  Conscious- 
ness m  the  scheme  of  Evolution.    And  for  this  reason  I  have 
placed  the  origin  of  Pleasures  and  Pains  very  low  down  in 
the  scale  of  conscious  life..^  Indeed,  if  we  contemplate  the 
subject  we  shall  find  it  difficult  or  impossible  to  imagine  a 
form  of  consciousness,  howevcf'  dim,  which  does  not  present 
m  a  correspondingly  undeveloped  condition,  the  capacitv  of 
preferring  some  of  its  states  to  others— that  is,  of  feeling  a 
distinction  between  quiescence  and  vague  discomfort,  which 
with  a  larger  accession  of  the  mind-element,  grows  into  the 
vivid  contrast  between  a  Pleasure   and  a  Pain.     I  think 
therefore,  it  is  needless  to  say  more  in  justification  of  the 
level  on  the  diagram  at  which  I  have  written  these  words. 

Memory  and  Association  of  Ideas. 

It  is  obvious  that  Memory  must  ne,  and  is,  a  faculty  which 
appears  very  early  in  the  development  of  Mind.  A  priori, 
this  must  be  so,  because  consciousness  without  memory  would 
be  useless  to  the  animal  possessing  it,  and  d  posteriori  we 
find  that  this  is  so  whether  we  contemplate  the  scale  of 
mental  evolution  in  the  animal  kingdom  or  in  the  growing 
child.  _  I  have  therefore  assigned  the  rise  of  Memory  to  the 
level  immediately  succeeding  that  which  is  occupied  by  the 
rise  of  Pleasures  and  Pains. 

In  a  previous  chapter*  I  have  endeavoured  to  show  that, 
even  before  the  dawn  of  Consciousness,  nervous  actions  of 
adjustment  when  frequently  repeated  present  conclusive 
evidence  that  the  nervous  machinery  concerned  in  them 
becomes  more  or  less  organically  adapted  to  perform  them, 
and  so  exhibits  the  objective  aspect  of  memory.  This  objec- 
tive aspect  I  spoke  of  as  the  memory  of  a  ganglion.  Since 
that  chapter  was  written,  M.  Ribot  has  published  his  excel- 

•  On  "  the  Physical  Basis  of  Mind." 


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112 


MENTAL  EVOLUTION  IN  ANIMALS. 


Hi 


lent  work  on  the  "Diseases  of  Memory,"  which  has  now 
been  translated,  and  forms  a  member  of  the  International 
Scientific  Series.  In  this  work  M.  Eibot  deals  fully  with  the 
complete  analogy  that  obtains  on  the  objective  side  between 
ganglionic  memory— or,  as  he  caUs  it,  organic  memon^— and 
the  physical  changes  in  the  cerebral  hemispheres  which  are 
concerned  in  true  or  conscious  memory.  I  should  like  to 
express  my  satisfaction  at  finding  so  singularly  close  a  corre- 
spondence between  the  views  of  M.  Eibot  and  myself  upon 
these  matters,  which  extends  into  so  many  detaUs  that  I  have 
left  my  chapter  already  referred  to  verbatim  as  it  was  oricd- 
naUy  written;  for  it  speaks  in  favour  of  the  truth  of  one's 
results  when  they  have  been  independently  arrived  at  by 
another  worker  in  the  same  field.* 

^     And  here  I  may  observe  that  I  also  agree  with  M.  Eibot 
in    his    view    that    the    phenomena    of  memory,  whether 
"organic"   or   "psychological,"    present  no  point  of  true 
analogy  with  any  such  purely  physical  phenomena  as  the 
permanent  effects  upon  a  photographic  plate  of   a  short 
exposure  to  light,  or  any  other  phenomena    where    living 
organisms  are  not  concerned.    I  further  agree  with  him  in 
his  view  that  the  earliest  analogy  we  can  find  to  memory  is 
to  be  sought  in  living  tissues  other  than  nervous,  and  that  it 
occurs  m  protoplasm.  Thus  he  quotes  Hering  to  the  effect  that 
muscular  fibre  "  becomes  stronger  in  proportion  to  its  use." 
To  this  It  may,  I  think,  be  objected  that  there  is  no  evidence 
of  individual  muscular  fibres  thus  gaining  in  strength  by 
use.  I  think  a  better,  because  a  more  unexceptionable,  parallel 
IS  afforded  by  the  fact  that  when  a  constant  galvanic  current 
IS  allowed  to  pass  for  a  short  time  through  a  bundle  of  mus- 
cular fibres,  in  the  direction  of  their  length,  and  is  then  opened 
a  change  is  found  to  have  been  produced  in  the  excitability 
of  the  fibres  such  that  they  are  less  excitable  than  before  to 
a  stimulus  supplied  by  again  passing  the  current  in  the 
same  direction,  and  more  excitable  to  the  stimulus  sup- 
plied by  passing  the  current  in  the  opposite  direction.    This 
memory  of  a  muscle  touching  the  direction  in  which  a  gal- 
vanic stimulus  has  passed  endures  for  a  minute  or  two  after 
the  current  has  ceased  to  pass  (Frog).    I  have  found  this 


•  Any  one  who  cares  to  trace  the  correspondence  may  do  so  by  comparinff 
my  chapter  above  aUuded  to  with  the  first  chapter  of  M.  Eibot'a  work. 


MEMORY  AND  ASSOCIATION  OF  IDEAS.  113 

curious  fact  to  hold  in  the  case  of  muscular  tissues  of  various 
animals,  from  the  Medusae  upwards.*    " 

Again   I  concur  with  M.  Eibot  in  h's  opinion  that  the 
physical  basis  of  memory  consists  partly  in  a  more  or  less 
permanent  molecular  change  or  "impress"  produced  upon 
the  nervous  element  affected  by  the  stimulus  which  is  re- 
membered,  and  partly  upon  "  the  establishment  of  stable 
connections  between  different  groups  of  nervous  elements" 
1  do  not  think  that  the  view  can  be  too  strongly  reprobated 
which  crudely  supposes  that  the  first  of  these  physical  con- 
ditions IS  alone  sufficient  to  explain  all  the  facts  of  memory 
and  therefore_  that  a  given  remembrance  is,  as  it  were  stored 
upm  a  particular  ceU,  as  a  particular  "impression"  upon 
the  substance  of  that  cell.     On  the  contrary,  as  M.  Eibot 
SHOW'S,     Lach  of  these  supposed  unities  (memories)  is  com- 
posed of  numberless  and  heterogeneous  elements ;  it  is  an 
association,  a  group,  a  fusion,  a  complexus,  a  multiplicity; 
....    Memory  supposes  not  only  a  modification  of 
nervous  elements,  hut  the  formation  among  them  of  determi- 
nate associatiom  for  each  particular  act.    We  must  not  how- 
ever, forget  that  this  is  pure  hypothesis— the  best  available 
one  no  doubt,  but  still  not  to  be  taken  as  implying  that  we 
really  know  anything  definitely  concerning  the  physical  sub- 
stratum of  memory."  ^   "^ 

Profound  however,  as  our  ignorance  unquestionably  is 
concermng  the  physical  substratum  of  memory,  I  think  we 
are  ut  least  justified  in  regarding  this  substratum  as  the  same 
botfi  m  ganglionic  or  organic,  and  in  conscious  or  psycholo- 
gical memory— seeing  that  the  analogies  between  the  two  are 
so  numerous  and  precise.  Consciousness  is  but  an  adjunct 
which  arises  when  the  physical  processes— owing  to  infre- 
quency  of  repetition,  complexity  of  operation,  or  other  causes— 
myolve  what  I  have  before  caUed  ganglionic  friction.  And 
this  view  IS  confirmed  by  the  large  and  general  fact  noted  in 

Pm  %lanT'vfj\^l^'"^'T'  ^^  t^^^'O'^o'^otor  Sj«tem  of  Medusa." 
vlL   pI     V       AT   •  }^^^'  ^^^'^  °"   "Modification   of  Excitability,"  ic 

Zty.  A  Z  ^^^  "n'^  ^""h  >'«°'  '^°«''««^  of  Anatomy  an/hysio'. 
log,/,  yol.  X.     Another  equally  good  instance  of  what  mar  be  termed  nroto- 

stimuli,  which  occur  more  or  less  in  aU  excitable  tissues,  i  e  wherever 
1  ving  protoplasm  is  concerned.      These  facts  are  that  if  ^  successfon  of 

moT«„nr^^'^'^'''^V*^°  ^'',?*^^^«  «««"«•  the  latter  becomes  piSe  si^e?y 
more  and  more  quick  as  well  as  more  and  more  energetic,  in  its  fesoonse^ 
each  stimulus  leaves  behind  it  an  organic  memory  of  itf  occurrence      ^        ' 


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114 


MENTAL  EVOLUTION  IN  ANIMALS. 


our  chapter  on  the  Physical  Basis  of  Mind,  that  conscious 
memory  may  become  degraded  into  unconscious  memory  by 
repetition;  associations  originally  mental  lapsing  into  asso- 
ciations that  are  automatic. 

Thus  much  being  premised  touching  the  physical  basis  of 
memory,  we  may  next  pass  on  to  consider  the  evolution  of 
memory  on  its  psychological  side. 

+T,-  P^  earliest  stage  of  true  or  conscious  memory  may  I 
think,  be  regarded  as  consisting  in  the  after-eflect  produced 
upon  a  sensory  nerve  by  a  stimulus,  which  after-effect  so 
long  as  it  endures,  is  continuously  carried  up  to  the  sensoriura 
feuch  for  instance,  is  the  case  with  after-images  on  the  retina 
the  after-pain  of  a  blow,  &c.*  ' 

The  next  stage  of  memory  that  it  appears  to  me  possible 
to  distinguish  by  any  definite  interval  from  the  first-named 
IS  tfiat  of  feeling  a  present  sensation  to  be  like  a  past  sensa- 
tion.    In  order  to  do  this  there  may  be  no  memory  of  the 
sensation  between  the  two  successive  occasions  of  its  occur- 
rence, and  neither  need  there  be  any  association  of  ideas 
Unly  this  takes  place ;  when  the  sensation  recurs  the  second 
third,  or  fourth  time,  &c.,  it  is  recognized  as  like  the  sensa- 
tion when  It  occurred  the  first  time— as  like   a  sensation 
which   is  not  unfamiliar.     Thus,  for  example,  accordincr  to 
bigismund,  who  has  devoted  much  careful  attention  to  the 
psychogenesis  of  infants,  it  appears  that  the  sweet  taste  of 
milk  being  remembered  by  newly-born  infants,  causes  them 
to  prefer  sweet  tastes  in  general  to  tastes  of  any  other  kind 
Ihis  preference  of  course  endures  long  after  the  time  of 
weaning  IS  past,  and  generally  continues  through  childhood; 
but  the  interesting  point  in  the  present  connection  is  that  it 
occurs  too  early  in  the  life  of  the  child  to  admit  of  our  sup- 
posing that  any  association  of  ideas  can  take  part  in  the 
process.    For  Sigismund  says  that  the  memory  of  the  taste  of 
milk  becomes  attached  to  the  perception  "  immediately," 
and  Preyer  states,  from  independent  observations  of  his  own 
that  the  preference  shown  for  sweet  tastes  over  tastes  of  all 
oth^  kinds  may  be  clearly  seen  as  early  as  the  first  day. 

The  next  distinguishable  stage  of  memory  is  reached 

when,  still  without  any  association  of  ideas,  a  present  sensa- 

tionis  perceived  as  unlike  a  past  one.     Thus,  again  turnincr 

to  the  observations  of  Sigismund  and  Preyer,  it  appears  from 

♦  Compare  Wundt,  Qrundzuge  der  philosophischen  Pst/chologie,  p.  791. 


MEMORY  AND  ASSOCIATION  OF  IDEAS. 


115 


them  that  after  the  accustomed  taste  of  milk  has  become  well 
fastened  m  the  memory  by  several  successive  acts  of  suckincr 
the  child  when  a  few  days  old  is  able  to  distinguish  a  chancS 
of  milk.     Similarly,  I  find  among  Mr.  Darwin's  MSS  the 
lollowing  note : — 

"  It  is  asserted  (by  Sir  B.  Brodie)  that  if  a  calf  or  infant 
has  never  been  suckled  by  its  mother,  it  is  very  much  easier 
to  bring  It  up  by  hand  than  if  it  has  sucked  only  once  So 
again,  Kirbyaiid  Spence  state  (from  Reaumur,  '  Entomolocry ' 
vol.  1,  p.  391)  that  larvae  after  having  '  fed  for  a  time  on  Sne 
plant  will  die  rather  than  eat  another,  which  would  have, 
been  perfectly  acceptable  to  them  if  accustomed  to  it  from 
the  first.' " 

It  will  be  observed  that  in  dealing  with  these  stages  of 
memory  m  very  young  inllmts,  where  as  yet  no  association  of 
Ideas  can  either  be  supposed  to  be  present  or  is  needed  to 
explain  the  facts,  we  at  once  encounter  the  question  whether 
the  memory  is  to  be  considered  as  reaUy  due  to  individual 
experience,  or  as  an  hereditary  endowment,  i.e.,  an  instinct 
And  here  it  becomes  apposite  to  refer  to  the  old  and  hicrhly 
interesting  experiment  of  Galen,  which  definitely  ans?vers, 
this  question  with  reference  to  animals.     For  soon  after  its 
birth,  and  before  it  had  ever  sucked,  Galen  took  a  kid  and 
placed  before  it  a  row  of  similar  basins,  filled  respectively 
with  milk,  wine,  oil,  honey,  and  flour.  The  kid,  after  examin- 
ing the  basins  by  smell,  selected  the  one  which  was  filled 
with  milk.     This  unquestionably  proves  the  fact  of  hereditary 
memory,  or  instinct,  in  the  case  of  the  kid ;  and  therefore  it 
IS  probable  that  the  same,  at  all  events  in  part,  applies  to  the 
case  of  the  child.    In  proof  of  which  I  may  allude  to  the 
experiments  of  Professor  Kuszmaul,  who  found  that  even 
prior  to  individual  experience  derived  from  suckinf^  milk 
newly-born  children  show  a  preference  for  sweet  tastes  over 
all  others.     For,  on  their  tongues  being  wetted  with  sugar  or 
salt  solutions,  vinegar,  quinine,  &c.,  the   new-born  infants 
made  all  manner  of  grimaces,  being  pleased  with  the  suoar 
solution,  but  with  the  others  showing  displeasure  by  a  "  sour 
face,"  a  "  bitter  face,"  and  so  on. 

But  although  we  freely  admit  that  the  memory  of  milk  is 
at  aU  events  in  large  part,  hereditary,  it  is  none  the  less 
memory  of  a  kind,  and  occur*  without  the  association  of  ideas. 
In  other  words,  hereditary  memory,  or  instinct,  belongs  to 


!i.'i 


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ilV! 


116 


MENTAL  EVOLUTION  IN  ANIMALS. 


I        ' 


!     I 


.'! 


.(« 


I? 


What  I  have  marked  off  as  the  second  and  third  stages  of 
conscious  memory  m  the  largest  acceptation  of  the  term-the 
stages,  that  IS,  where,  without  any  association  of  ideas  a  pre- 
sent sensation  is  perceived  as  like  or  unlike  a  past  one  It 
makes  no  essential  difference  whether  the  past  sensation  was 
actually  experienced  by  the  individual  itself,  or  bequeathed 
to  It,  so  to  speak,  by  its  ancestors.  For  it  makes  no  essential 
difference  whether  the  nervous  changes  which  constitute  the 

rtrfnTfif' P??  .°^  ^H  Pf ^^^P^^ve  aptitude  were  occasioned 
during  the  hfe-time  of  the  individual,  or  during  that  of  the 
species  and  afterwards  impressed  by  heredity  on  the  indi- 
vidual.    In  either  case  the  psychological  as  well  as  the 
physiological  result  IS  the  same  ;  a  present  sensation  is  alike 
perceived  by  the  individual  as  like  or  unlike  a  past  sensation. 
It  IS  not  easy  at  first  to  grasp  the  truth  of  this  statement; 
but  the  source  of  the  difficulty  is  in  not  clearly  distinauish- 
ing  between  memory  and  the  association  of  ideas.     MSmorv 
inits  lower  stages  which  we  are  now  considering  has  in  mv 
opinion  nothing  to  do  with  the  association  of  ideas.     It  only 
has  to  do  with  perceiving  a  p^-esent  sensation  as  like  or  unlike 
a  past  sensation,  which  never  can  have  formed  the  object  of 
an  idea  between  times,  and  which  does  not  even  arise  as  an 
Ideal  remembrance  when  the  sensation   again   occurs     In 
other  words,  there  is  no  act  of  conscious  comparison  between 
tlie  two  sensations ;  there  is  not  even  any  act  of  ideation  • 
but  the  past  sensation  has  left  its  record  in  the  nervous  tissues 
ot  the  animal  m  such  wise   that  when  it  again  occurs  it 
emerges  into  consciousness  as  a  feeling  that  is  familiar~or  if 
another  unlike  sensation  takes  its  place,  this  emerges  into 
consciousness  as  a  feeling  that  is  not  familiar.     And  whetlier 
such  feelings  of   familirrity  or  unfamiliarity  arise  in  the 
experience  of  the  individual  or  in  that  of  the  species,  makes 
as  I  have  said,  no  essential  difference  either  in  the  physiolo- 
gical or  m  the  psychological  aspect  of  the  case. 

As  showing  how  close  is  the  connection  between  here- 
ditary memory,  or  instinct,  and  memory  individually  acquired. 
1  shall  briefly  state  some  very  interesting  experiments  which 
were  made  by  Professor  Preyer  on  newly-hatched  chickens. 
±le  laid  before  a  newly-hatched  chicken  some  cooked  white 
ot  egg,  some  cooked  yolk  of  egg,  and  some  millet  seed.  The 
chick  pecked  at  all  three,  but  no  more  frequently  at  the  two 
latter  than  it  did  at  pieces  of  egg-shell,  grains  of  sand,  or  the 


MEMORY  AND  ASSOCIATION  OP  IDEAS. 


117 


spots  and  cracks  of  a  wooden  floor  on  which  it  was  placed. 
But  at  the  yellow  yolk  it  pecked  often  and  earnestly.  He 
then  removed  all  three  substances,  and  after  the  lapse  of  an 
hour  replaced  them.  The  chick  instantly  recognized  them  all 
as  proved  by  its  immediately  beginning  to  devour  them  while 
flowing  a  complete  disregard  of  all  other  and  inedible  objects, 
whip  nf  A  ^^P^:^°^fnt  the  chick  only  once  tasted  the 

white  of  egg,  and  only  took  a  single  millet  seed.  The  experi- 
ment  therefore  shows  how  apt  a  young  chicken  is  to  learn  by 
Jp..rV  'Ir^  experience,  while  in  the  opinion  of  Pro- 
fessor Preyer  the  original  preference  shown  to  the  yolk  of 
egg  proves  an  inherited  faculty  of  taste-discrimination. 

Ihese  experiments  serve  to  introduce  us  to  the  sta^e  of 
Memoryat  which  the  Association  of  Ideas  is  first  concern'ed- 
tn^'^^Pl"  "?  throughout  all  subsequent  stages  consti- 
tutes  what  may  be  termed  the  vital  principle  of  Memory- 
for  the  chickens  which  first  pecked  at  inedible  objects  in  the 
presence  of  edible  ones,  and  an  hour  later  were  able  to  dS 

SL^Tlf-^'"'  two  classes  of  objects,  must  have 
estabhshed  a  dehnite  association  of  ideas  between  each  of  the 

tSl^tu^^^^''''Ai^\^'''^''  ^^P^^^«^^«  ^ith  reference  0 
1^  tlli  H  rV"""^'^^^  '?''"'^''-  ^^^  '^  ''  noteworthy  that, 
as  these  definite  associations  were  established  so  quickly  and 
as  the  result  of  only  a  single  individual  experience  i/each 
case,  we  can  scarcely  avoid  concluding  that  heredity  must 

as'In  thP.'^''^''r  ?'*  the  largest,  part^n  the  proceX^u 
as  m  the  case  of  distinguishing  from  the  first  the  boiled  yolk 

IJf'  Y^T'^  J^PP^f"  ^^^^  ^^^^dity  had  the  exclusive 
part  *    And  this  shows  how  closely  the  phenomena  of  heie- 

atthT,fH^'^r  '^^f^^  '\'^''''  °^  ^^^ividual  memory; 
a  socfation^  n^  "7^1'''''  "^  mnemonics,  where  the  simpi' 
assoc  ation  of  ideas  first  occurs  in  very  youncr  animals  it  i<? 
practically  impossible  to  disentangle  the  effects%f  EditLy 
memory  from  those  of  individual  "erecucary 

Association  of  Ideas. 
I  shall  reserve  for  my  chapter  on  Imagination  a  full 

to  ta*s^'=;t^L'rr^^^^^^^^^^  reference 

chicken  ran  nnv^-  i,o^«  t   ■T^J"^'^  supposes,  seeing  that  in  nature  a  voiinir 

mauj  seeds  are  more  or  less  jeUow  in  tint?       ^  eelection,  as  . 


i|i' 


4      '■ 


i 


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1 

J,  : 

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i 
i    - 

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Li 

118 


MENTAL  EVOLUTION  IN  ANIMALS. 


V 


! 


IH 


analysis  of  Ideation.  But  in  connection  with  Memory  it  is 
necessaiy  to  touch  upon  the  Association  of  Ideas,  and  there- 
fore I  sliall  do  so  now,  notwithstanding  the  disadvantage 
which  arises  from  considering  the  property  that  ideas  pre- 
sent of  becoming  associated  before  we  consider  the  ideas 
themselves.  The  truth  is  that  here  as  elsewhere  one  labours 
under  a  difficulty  in  dealing  with  the  faculties  of  Mind  in  the 
probable  order  of  their  evolution,  from  the  fact  that  these 
faculties  require  to  be  treated  separately,  althougli  they  have 
not  arisen  separately,  or  in  historical  sequence.  Tlierefore 
one  has  to  meet  the  difficulty  by  occasionally  forestalling  in 
earlier  chapters  general  and  well-known  principles,  the°de- 
tailed  consideration  of  which  forms  the  subject-matter  of 
later  chapters.  Such  a  difficulty  arises  now,  and  necessitates 
a  somewhat  premature  treatment  of  what  I  may  call  the 
elements  of  ideation. 

Throughout  the  present  work  I  shall  use  the  word  Idea 
in  its  widest  sense.  As  few  terms  have  been  used  with  a 
greater  variety  of  meanings,  I  think  it  is  better  to  state  here 
at  the  outset  what  I  take  to  be  its  most  general  meaning, 
and  therefore  the  one  which,  as  I  have  said,  I  shall  always 
attach  to  it. 

If  after  looking  at  a  tree  I  close  my  eyes  and  then  arouse 
a  mental  picture  of  what  I  have  just  seen,  I  may  say  indif- 
ferently that  I  remember  or  imagine  the  tree,  or  that  I  have 
an  idea  of  it.  The  idea  in  this  case  would  be  simple  or  con- 
crete—the mere  memory  of  a  previous  sensuous  perception. 
Now  between  this  and  the  highest  product  of  ideation  there 
is  all  the  interval  between  the  lowest  and  the  highest  develop- 
ment of  Mind.  The  range  of  meaning  over  which  the  terra 
Idea  thus  extends  has  seemed  to  many  writers  inconveniently 
large,  and  they  have  therefore  imposed  upon  it  various  limi- 
tations. But  as  all  such  limitations  are  of  a  purely  artificial 
kind,  I  shall  nowhere  limit  the  term  in  itself,  but  whenever  I 
have  occasion  to  specify  one  or  other  class  of  ideas,  I  shall  do 
so  by  employing  the  convenient  adjectives.  Concrete,  Abstract, 
and  General,  in  the  senses  which  I  shall  have  to  explain 
further  on.  Meanwhile  it  is  enough  to  say  that  whenever 
I  employ  the  term  Idea  alone,  I  mean  it  to  be  a  generic 
term. 

We  have  already  seen,  while  treating  of  the  obverse  or 
physiological  side  of  ideation  (in  the  chapter  on  the  Physical 


iil 


ASSOCIATION  OF  IDEAS. 


119 


Basis  of  Jlind)  that  ideas  have  a  strong  tendency  to  cohere 
togotaer  in  groups,  so  as  to  constitute  one  compound  idea 
out  of  many  simpler  or  more  elementary  ideas:  and  also 
that  they  show  no  leas  strong  a  tendency  to  cohere  together 
in  concatenated  series,  such  tliat  the  arousing  of  the  first 
member  determines  the  successive  arousing  of  the  other 
members.     On  its  physiological  side,  as  we  saw,  this  is  pre- 
cisely analogous  on  the   one  hand  to  the  co-ordination  of 
muscular  movements  in   space  (i.e.,  the  grouping  of  such 
movements  to  form  a  simultaneous  act,  such  as  striking),  and 
on  the  other  hand  to  the  co-ordination  of  muscular  movements 
in  time  (i.e.,  tlie  grouping  of  such  movements  to  perform  a 
serial  act,  such  as  vomiting).    Now  it  is  found  by  observa- 
tion that  this  cohesion  of  ideas  is  determined  either  by  con- 
tiguity or  by  similarity.    This  fact  is  too  well  and  generally 
known  to  call  for  more  than  a  bare  statement. 
_    Association  by  contiguity  is  more  primitive  than  associa- 
tion by  the  similarity,  for  in  order  that  there  should  be  asso- 
ciation by  similarity,  the  similarity  must  be  perceived;  and 
this  implies  a  higher  level  of    mental  evolution  than  is 
required  to  establish  an  association  by  contiguity— which,  as 
we  have  seen,  may  be  established  even  in  non-mental  nervous 
processes,  while  there  is  nothing  truly  analogous  to  associa- 
tion by  similarity  observable  in  such  processes.* 

But  it  will  be  observed  that  even  association  of  ideas  by 
contiguity  of  the  simplest  possible  kind,  implies  a  hi<Ther 
development  of  the  powers  of  memory  than  any  of  the  three 
stages  of  memory  which  I  have  already  indicated.  For  now 
there  is  not  merely  the  memory  of  a  past  sensation  (which  is 
dormant  till  aroused  by  another  like  or  unlike  sensation); 
but  there  is  the  memory  of  at  least  two  things,  and  also  the' 
memory  of  a  previous  relation  of  sequence  between  them. 

•  The  nearest  approach  to  such  an  analogy  is  perhaps  to  be  found  in  the 
curious  fact,  which  1  find  to  hold  true  in  most  persons,  that  if  a  pencil  is 
token  in  each  hand,  and  while  the  habitual  signature  is  being  written  with 
the  right  hand,  moving  from  left  to  right,  the  movements  are  imitated  by  the 
lett  iiand  moving  in  the  opposite  direction,  the  signature  will  be  found  to 
have  been  written  backwards  by  the  left  hand,  and  even  the  hand-writing  can 
be  recogmzed  on  holding  the  paper  before  a  mirror.  As  the  left  hand  may 
never  have  performed  this  feat  before,  and  cannot  perform  it  unless  the  rijiht 
hand  18  working  simultaneously,  the  case  looks  hke  one  of  association  bv 
BimUanty.  But  I  think  it  is  really  due  to  association  bv  contiguity  •  and 
the  same  appUes  to  the  extreme  difficulty  of  moving  the  two  hand/simul. 
taneously  as  if  carding  wool  in  opposite  directions. 


IMI^ 

!'! 

IB' 

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120 


MENTAL  EVOLUTION  IN  ANIMALS. 


This,  therefore,  we  may  mark  off  as  another  distinct  sta^e  in 
the  evolution  of  mnemonics.  ° 

After  this  stage  has  advanced  to  a  considerable  extent,  so 
that  numerous  concrete  and  compound  ideas  are  associated  in 
a  great  many  chains  of  more  or  lees  length  or  number  of 
links  a  sufficient  body  of  psychological  data  has  been  fur- 
nished to  admit  of  the  next  stage  of  memory  being  reached 
u^rru^  °^  association  by  similarity.  Professor  Bain  remarks ! 
1  he  force  of  contiguity  strings  together  in  the  mind  words 
that  have  been  uttered  together ;  the  force  of  similarity  brings 
fomard  recollections  from  different  times  and  circumstances 
and  connexions,  and  makes  a  now  train  out  of  many  old 
ones.  *  And  as  in  these  higher  planes  of  human  memory,  so 
m  the  lower  ones  of  animal  memory ;  association  by  similarity 
implies  a  better  development  of  ideation  than  does  associa- 
tion by  contiguity. 

The  next  and  final  stage  of  Memory  ia  attained  when 
reflection  enables  the  mind  to  localize  in  the  past  the  time 
when  an  event  remembered  took  place.  This  is  the  sta.^e  of 
memory  which  is  called  EecoUection,  and  occurs  in  all  ^ases 
where  the  mind  knows  that  some  particular  association  of 
Ideas  has  previously  been  formed,  and  is  therefore  able  deli- 
berately to  search  the  memory  until  the  particular  association 
required  is  brought  into  the  light  of  consciousness. 

I  have  now  given  a  sketch  of  the  successive  stages  in  the 
evolution  of  Memory,  drawing  a  line  to  mark  off  a  stacre 
wherever  I  have  been  able  to  distinguish  a  place  where  °a 
iine  could  be  drawn.  It  is  needless  to  say  that  here,  as  in  all 
similar  cases,  I  deem  these  lines  to  be  of  a  purely  arbitrary 
character,  and  introduce  them  only  to  give  a  general  idea  of 
the  upward  growth  of  a  continuously  developing  faculty  I 
shall  now  conclude  this  chapter  by  briefly  glancing  at  the 
animal  kingdom  and  the  growing  child  with  reference  to  the 
evolution  of  Memory. 

Taking  first  the  case  of  the  child,  I  have  assigned  the 
seventh  week  as  the  appropriate  age  at  which  to  mark  the 
first  evidence  of  memory  in  the  association  of  ideas.  I  do  so 
because  I  have  observed  that  this  is  the  age  at  which  hand- 
fed  children  first  recognize  the  feeding-bottle,  i.e.,  an  artificial 
object  without  smell  or  other  quality  that  can  arouse  any 
ancestral  instincts,  and  one  which  vounj?  infants  alwayp 


instincts,  and  one  which 

*  Senses  and  Intellect,  p.  469. 


young 


;  i;  ■, 


1 


ASSOCIATION  OP  n)E.\8, 


121 


Loci- 


appear  to  recognize  earlier  than  any  other  ohject. 
indeed,  mentions  recognition  of  the  feeding-bottle  as  con- 
temporaneous with  that  of  the  rod;  but  as  our  ideas  on 
matters  of  education  have  undergone  some  improvement 
since  his  time,  this  statement  would  now  be  difficult  to 
verify.  In  my  own  child  I  observed  that  the  power  of  asso- 
ciating ideas  extended  in  the  ninth  week  from  the  feeding- 
bottle  to  the  bib,  which  was  always  and  only  put  on  before 
feeding;  for  as  soon  as  this  was  put  on  the  child  used  to 
cease  to  cry  for  the  bottle.  At  this  age,  also,  I  observed 
that  when  I  put  her  woollen  shoe  upon  her  hand  she  gazed 
at  it  intently,  as  if  perceiving  that  some  curious  change  had 
come  over  the  habitual  appearance  of  the  hand.  At  ten  weeks 
she  knew  her  bottle  so  well  that  she  would  place  the  nipple 
of  it  in  her  own  mouth,  and,  when  allowed  to  do  so,  would 
hold  the  bottle  herself  while  sucking.  Generally,  however, 
she  would  fail  in  her  attempts  at  introducing  the  nipple  into 
her  mouth,  clearly  from  a  lack  of  co-ordinating  power  in  her 
muscles — the  nipple  striking  various  parts  of  her  face.  She 
would  then  cry  for  the  nurse  to  help.  Preyer  says*  that  at 
eight  months  old  his  child  was  able  to  classify  all  glass  bottles 
as  resembling,  or  belonging  to  the  same  order  of  objects,  as  a 
feeding-bottle.  I  may  add  that  at  seven  weeks  old  my  child 
used  to  cry  when  left  alone  in  a  silent  room  for  a  few  minutes 
— a  fact  which  also  seems  to  show  a  rudimentary  power  of 
associating  ideas,  with  the  consequent  perception  of  a  change 
in  the  habitual  environment. 

Turning  now  to  the  animal  kingdom,  the  first  evidence  of 
memory  that  I  have  found  in  the  psychological  scale  is  in  the 
Gasteropoda,  and  consists  in  the  Limpet  returning  to  its 
groove  in  the  rock  after  having  been  crawling  about  upon  a 
browsing  excursion.t  This  fact,  I  think,  clearly  proves  the 
power  of  remembering  locality,  and  as  such  a  grade  of  memory 
can  scarcely  be  regarded  as  the  earliest,  we  may  reasonably 
suppose  that  the  faculty  really  occurs  still  lower  in  the  psycho- 
logical scale  of  animals,  although  we  have  not  as  yet  any 
observations  to  prove  the  fact.  Moreover,  as  Oysters  learn  by 
individual  experience,  acquired  in  the  "Oyster-schools,"  to 
keep  their  shells  closed  for  a  much  longer  time  than  is  natural 
to  uneducated  individuals,  J  we  must  conclude  that  a  dim  power 


•  Loc.  cit.,  p.  42. 

t  Aiiimai  Lniellignnve,  pp.  28-9. 


J  Ibid.,  p.  25, 


" ,  "  >  I 


^1 ' 

■  •,■: 

i 

•1 

In  J 


122 


MENTAL  EVOLUTION  IN  ANIMALS. 


if 


ii  .' 


ifiii 


• 

1^^ 

I  ' 


of  memory  IS  also  present  in  the  division  of  the  Mollusca. 
ino  Kazor-fish,  likewise,  shows  memovv,  and  this  in  a  hi"h 
deforce,  inasmuch  as  if  only  once  alarmwl  upon  comin^  to  the 
surtace  of  its  burrow,  it  cannot  be  aj,'ain  in(hiced  to  approach 
the  surface  for  a  long  time,  even  by  the  application  of  irri- 
tants      btiU  more  remarkable  is  the  level  of  development  to 
which  memory  has  attained  in  the  Snail,  if  the  observation  of 
Mr.  Lonsdale  is  to  be  accepted  of  the  Ildix  pomatia,  which, 
atter  leaving  its  sickly  mate  and  crawling  over  a  garden  wall 
returned  next  day  to  the  place  where  it  had  left  its  mate.f 
Hut  the  hii/hest  level  to  which  the  development  of  memory 
attains  in  the  Mollusca  is  unquestionably  in  the  Cephalopoda. 
tor  according  to  Hollniann  an  Octopus  remembered  its  en- 
countivr  with   a   lobster  in  a  remarkable    manner,!  while 
according  to  Schneider  these  animals  learn  to  know  their 
keepers.J 

Seeing  that  memory  in  various  stages  of  development  thus 
unquestionably  occurs  among  the  Mollusca,  I  thought  it  worth 
while  to  try  some  experiments  in  tliis  connection  with  the 
Jb^chinodermata,  but  they  all  yielded  negative  results.    It  has 
however,  been  alleged  that  if  a  star-fish  be  removed  from  its' 
eggs,  It  will  crawl  back  again  to  the  place  where  they  were- 
and  if  this  statement  were  confirmed,   it  would  of  course 
prove  memory  in  the  Echinodermata.  Hitherto  I  have  myself 
had  no  opportunity  of  testing  it,  and  therefore  my  expe- 
riments were  confined  to  endeavouring  to  teach  star-fish  a 
tew  simple  lessons,  which,  as  I  have  already  implied,  they 
would  not  learn.     I  am  more  surprised  with  my  failure  in 
this  respect  with  the  higher  Crustacea;  for  although  I  have 
tried  similar  experiments  with  them,  I  have  never  been  able 
to  teach  them  the  simplest  things.    Thus,  for  instance,  I  have 
taken  a  hermit  crab,  put  it  into  a  tank  filled  with  water,  and 
when  he  had  protruded  his  head  from  the  sheU  of  the  whelk 
in  which  he  was  residing,  I  gently  moved  towards  him  a  pair 
ot  open  scissors,  and  gave  him  plenty  of  time  to  see  the 
glistening  object.     Then,  slowly  including  the  tip  of  one  of 
his  tentacles  between  the  open  blades,  I  suddenly  cut  off  the 
tip     Of  course  the  animal  immediately  drew  back  into  the 
Shell,  and  remained  there  for  a  considerable  time.     When  he 
again  came  out  I  repeated  the  operation  as  before,  and  so  on 

•  Animal  Intelligence,  p.  26.  f  Ibid.,  p.  27.        J  Ibid.,  p.  30. 


:l 


% 


It  I' 


i: 


ASSOCIATION  OF  IDEAS. 


123 


fntfl  crrmtnnmhcT  of  timoH.  till  all  the  tentnclos  hnd  been 
progressively  cut  away  little  by  little.  Yet  the  ai.in  ,1  m-vpr 
earnt  to  associate  the  appenince  of  the  s  i  sZ  t  tl  o 
eflect  which  always  followed  it.  and  so  never  drew  n  ur  i^ 
the  snip  had  been  given.     Nevertheless,  that  inen.orvdoea 

quoted  in  Aiiiinul  Intelligence"  (p.  233).  concerning  a 
bbster  mounting  guard  upon  a  heap  of  shhJo  beneath  which 
It  had  previously  hidden  some  food  °  ^ 

In  another  class  of  the  Articulata.  liowover.  the  faculty  of 
memory  has  been  developed  to  an  extrac.rclinaryde.ne7 and 
far  surpasses  that  which  han  been  attained  by  any  otl  er'c  ass 
of  Invertebrata.    The  class  of  the  Articulata  t^o  which  I  alliuL 
are  the  Insects,  and,  more  particularly,  the  11^^^" 
Without  quoting  in  ..7m.o  the  evidence  on  thi  Yi  ul  vvh  ch 
has  already  been  given  in  my  previous  work,  it  is  enough  to 
say  in  general  terms  that  ants  and  bees  are  unquestionably 
able  to  remember  the  places  where  many  months^ befme  they 
have   obtained  honey  or  sugar,  &c.;   and  will  also    w  en 
occasion  requires,  return  to  nests  and  hives  which  tlievTmve 
deserted  the  year  before.    Many  interesting  oSrvations    ave 
also  been  made  on  the  rate  of  acquisition  and  the  en' th  or 
duration  of  particular  memories  in  these  animals    which 
however  it  is  needless  for  me  again  to  quote."     PeSmps  the 
mos    interesting  of  these  are  the  observations  of  sTr^John 
Lubbock  on  bees  gradually  learning  to  know  the  difference 
between  an  open  and  a  closed  window,  and  the  observations 
of  Messrs.  Bates  and  Belt  on  the  sand-wasps  carefulirteac 
ng  themselves  (by  taking  mental  notes  of  landmarksrtl  e 
ocalities  to  whic3h  they  intend  to  return  in  orSer  to  sture 
the  prey  which  they  have  temporarily  concealed     Incidenal 
evidence  of  memory  in  other  orders  of  Insects  wial^  be 
PP  ^^r'otrT"  '°  "^^  rr'""'  ^yon^^yi'^.,  for  BceUes 
%;  p  230  '^''  ^'        '  ""''^  ^°'  ^^'^  '^^"^"^^^  House- 

Turniug  now  to  the  Vertebrata,  we  find  that  in  Fish 
memory  is  certainly  present,  although  it  never  reaches  S 
than  such  a  degree  of  development°as  is  implied  by  rerem! 
bering  in  successive  years  the  locality  for  spiwnin/leamrc. 
to  avoid  baits,  removing  young  from  a  nesUvhidrhas  beef 


^f 


m 


i 


m 


;  1  '  I 

i       i    :     !■  t 


124 


MENTAL  EVOLUTION  IN  ANIMALS. 


•f  n' 


disturbed,  and  associating  the  sound  of  a  bell  with  the  arrival 
■    or  lood,* 

Batrachians  and  Reptiles  are  able  to  remember  localities 
and  also  to  identify  persons.f  The  annual  migration  of 
lurtles  further  proves  the  duration  of  memory  for  at  least  a 
year. 

In  Birds  the  power  of  memory  has  ac'vanced  considerably 
beyond  that  of  remembering,  as  in  the  case  of  the  swallow, 
the  precise  locality  of  their  nests  from  season  to  season,  and 
even  beyond  that  of  identifying  persons  from  year  to  yeart 
±  or  the  facts  which  I  have  previously  detailed  at  length 
touching  the  acquisition  by  talking  birds  of  tones,  words  and 
phrases,  show  not  only  an  exceedingly  high  development  of 
the  powers  of  special  association,  but  even  the  power  of 
genuine  recollection  to  the  extent  of  kno^ving  that  theie  is  a 
missing  hnk  in  the  train  of  a  previously  formed  association, 
and  of  purposely  endeavouring  to  recover  it.  Quotations 
from  Dr.  Wilks,  Mr.  Venn,  and  Mr.  Walter  Pollock  were  also 

?w^V"^  °^^®^'  *°  ®^^^  ^^^^  ^^^®^*  ^^^  careful  observation 
that  the  process  of  forming  special  associations  is  in  such 
cases  identical  with  that  which  occurs  in  man.§ 

Among  Mammals  the  highest  development  of  memory  is 
presented  by  the  Horse,  Dog,  and  Elephant.  Thus  there  is 
unexceptionable  evidence  of  a  horse  remembering  a  road  and 
a  stable  after  an  interval  of  eight  years  ;||  of  a  dog  remem- 
bering the  sound  of  his  master's  voice  after  an  interval  of  five 
years,!  and  the  sound  of  a  clinking  collar  after  an  interval  of 
three  years  ;f  and  of  an  elephant  remembering  his  keeper 
alter  having  run  wild  for  an  interval  of  fifteen  years.**  It  is 
probable,  also,  that  if  observations  were  made,  the  memory  of 
Monkeys  would  be  found  to  be  very  retentive,  as  it  certainly 
IS  most  minute,  and  largely  assisted  by  the  intentional  efforts 
01  the  animals  themselves.tt 

•  See  Animal  Intelligence,  pp.  248-51.  f  Ihid.,  pp.  254-62. 

:  Ihid    p.  266.  §  For  all  these  facts,  see  ibid.,x>p.  266-70. 


PERCEPTION. 


125 


ii  i 


'^1 


CHAPTER  IX. 

Perception. 

At  the  level  marked  18  I  represent  the  rise  from  Sensa- 
tion to  Perception.  By  this  term  I  mean,  in  accordance 
with  general  usage,  the  faculty  of  cognition.  "  The  contrast 
between  Sensation  and  Perception  is  the  contrast  between 
the  sensitive  and  the  cognitive,  intellectual,  or  knowledge- 
giving  functions."  (Bain.)  "  Perception  is  an  establishment 
of  specific  relations  among  states  of  consciousness ;  and  this 
is  distinguished  from  the  establishment  of  these  states  of 
consciousness  themselves,"  which  constitutes  Sensation. 
(Spencer.)  "  In  Perception  the  material  of  Sensation  is 
acted  on  by  the  mind,  which  embodies  in  its  present  attitude 
all  the  results  of  its  past  growth."     (Sully.) 

Sensation,  then,  does  not  involve  any  of  the  powers  of 
the  intellect  as  distinguished  from  consciousness,  but  Percep- 
tion implies  the  necessary  occurrence  of  an  intellectual  or 
cognitive  process,  even  though  it  be  a  process  of  the  simplest 
possible  kind.  The  term  Perception,  therefore,  may  be 
applied  to  all  cases  where  a  process  of  cognition  occurs, 
whether  such  process  arises  directly  or  indirectly  out  of  sen- 
sation ;  thus  it  is  equally  correct  to  say  that  we  perceive  the 
colour  or  the  scent  of  a  rose,  and  that  we  perceive  the  truth 
or  the  probability  of  a  proposition. 

Other,  .'se  phrased  we  may  state  the  distinction  between 
Sensation  and  Perception  thus.  A  sensation  is  an  elementary 
or  uudecomposable  state  of  consciousness,  but  a  perception 
involves  a  process  of  mentally  interpreting  the  sensation  in 
terms  of  past  experience.  For  instance,  there  is  a  closed  book 
lying  on  the  table  before  me ;  my  eyes  have  been  resting  on 
its  cover  for  a  considerable  time  while  I  have  been  thinking 
how  I  should  arrange  the  material  of  the  present  chapter. 
All  that  time  I  have  been  receiving  a  visual  sensation  of  » 


,1'  i 


■il  ; 


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126 


MEXTAL  EVOLUTION  IN  ANIMALS. 


I     ft 


uu 


i      'ii 


I  I 


particular  kind;  but.  as  I  did  not  attend  to  it.  tlie  sensation 
did  not  involve  any  element  of  cognition,  and  therefore  did 
not  minister  to  any  act  of  perception.  All  at  once,  however 
I  became  conscious  that  I  v.as  looking  at  a  book  and  in 
cognizing  that  the  particular  object  of  sensation  was  a  book 

tJllZr^  f ''.  T  "^  P«^.«^Pti°n-  In  other  words.  I  men- 
tally interpreted  the  sensation  in  terms  of  past  experience  •  I 
made  a  mental  synthesis  of  the  qualities  of  the  object  and 
assigned  it  o  the  class  of  objects  which  had  pSusly 
produced  a  like  sensation.  pieviousiy 

teiJs'JSnl?'.*^''''''  ^  "^fntal  classifying  of  sensations  in 
teimsof  past  experience,  whether  ancestral  or  individual  •  it 
IS  sensation  2^lus  the  mental  ingredierL  of  interpretation. 
Now  as  a  condition  to  the  possibility  of  this  incrredient  it  is 
clearly  essential  that  there  should  be  present  fhe  power  of 

^r^^'h  ^''  '^^^  ^l  ^  ^'^"°^^  °^  P^^t  experience  can  the 
process  be  conducted  of  identifying  present  sensations  or 
experiences    as  resembling    past    oSes".     Therefore   in    the 
diagram  I  have  placed  the  dawn  of  Memory  on  the  level 
Se     tnTh%''  ^^^^"^^^"cultyof  Perception  ^akesTts 
Itfni.inc    o   ^^^«.f  "^^.^nd  Perception  are  represented   as 
attainmg   a  considerable  vertical   elevation    from    base    to 
apex,  te.,  from  their  first  origin  to  their  completed  evolution. 
nl  l^     j'i"'S^'*  ^?  ^^'°  represented  is  evident  if  we  reflect 
on  the  difference  m  the  sensuous  faculties  of  a  medusa  and 
an  eagle,  or  between  the  perceptive  faculties  of  a  limpet  and 
a  man.     It  may,  indeed,  be  thought  that  in  my  representative 
diagram  I  have  not  allowed  enough  for  such  differences,  and 
therefore  have  made  the  vertical  elevation  of  these  branches 
too  low.  But  here  we  must  remember  that  in  the  case  of  Sen- 
sation as  already  shown,  the  advance  of  the  faculty  from  its 
earliest  to  its  latest  stages  consists  essentially,  on  its  morpho- 
logical aspect,  of  a  greater  and  greater  degree  of  specializa- 
tion of  end-oi;gans  of  nerves;  and  I  think  that  the  degree  of 
such  advance  is  sufficiently  expressed  by  the  vertical  elevation 
Which  I  have  given  to  the  branch  in  question,  seeing  how 
much  more  intricate  must  be  the  morphological  development 
ot  the  nerve-tissues  which  are  concerned  in  ministering  to 
the  next  and  to  all  succeeding  faculties.     And,  as  regards 
Perception,  we    must   remember  that  in  its  more  hTahly 
elaborated  phases   this  faculty  shades  off  into  the  higher 
representative  branches  marked  "Imagination,"  &c.;  so  that 


PERCEPTION. 


127 


the  branch  marked  "  Perception  "  is  not  intended  to  include 
all  that  might  possibly  be  included  by  the  term  if  we  did  not 
eeparately  name  the  higher  faculties  to  which  I  allude. 

Now  concerning  the  development  of  Perception,  I  may 
here  make  a  general  remark,  which  is  first  applicable  at  this 
stage  of  mental  evolution,  and  which  continues  to  be  appli- 
cable to  the  development  of  all  the  faculties  which  we  have 
subsequently  to  consider.   This  remark  is  that  we  have  ceased 
to  possess  any  data  of  a  morphological  kind— such  as  we  had 
m  the  case  of  Sensation  and  the  pre-mental  faculties  of 
adjustment— to  guide  us  in  our  estimate  of  the   degree  of 
elaboration  to  which  the  faculty  has  attained.     That  morpho- 
logical evolution  has  here,  as  in  the  coarser  instanc3  of  Sen- 
sation, always  gone  hand  in  hand  with  psychical  evolution,  is 
amply  proved  in  a  general  way  by  the  advancing  complexity 
of  the  central  nerve-organs  ;  but  just  because  this  complexity 
IS  so  great,  and  the  steps  in  morphological  evolution  which  it 
represents  so  refined,  we  are  totally  at  a  loss  to  follow  the 
process  on  its  morphological  side  ;  we  are  unable  even  dimly 
to  understand  the  mechanisms  which  we  see.     Therefore,  in 
order  to  estimate  the  ascending  grades  of  excellence  which 
these  mechanisms  present,  we  require  to  look  to  what  we  may 
most  conveniently  regard  as  the  products  of  their  operation ; 
we  have  to  use  the  mental  equivalents  as  indices  of  the  mor- 
phological facts. 

We  have  seen  that  Perception  is  essentially  a  process  of 
mentally  interpreting  Sensation  in  terms  of  past  experience, 
ancestral  or  individual.  The  successive  steps  in  the  elabora- 
tion which  this  process  undergoes  in  the  course  of  its 
evolution  must  now  be  considered. 

The  first  stage  of  Perception  consists  merely  in  perceivin« 
an  external  object  as  an  external  object,  whether  by  the  sense 
of  touch,  taste,  smell,  hearing,  or  sight.  But  confining  our- 
selves, for  the  sake  of  brevity,  to  the  sense  of  sight,  in  this 
stage  Perception  simply  amounts  to  a  cognition  of  an  object 
in  space,  having  certain  space  relations  with  otlier  objects  of 
perception,  and  especially  with  the  percipient  organism. 

The  next  stage  of  Perception  is  reached  when  the  simplest 
qualities  of  an  object  are  re-cognized  as  like  or  unlike  the 
qualities  presented  by  such  an  object  in  past  experience.  The 
most  universal  of  such  qualities  in  objects  pertain  to  size 
form,  colour,  light,  shade,  rest,  and  motion  ;  less  universally 


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Ij  :, 


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«- 1,  -  f 


123 


MENTAL  EVOLUTION  IN  ANIMALS. 


such  qualities  pertain  to  temperature,  hardness,  softness, 
roughness,  smoothness,  and  other  qualities  appealing  to  the 
sense  of  touch,  as  well  as  qualities  appealing  to  the  senses  of 
smell,  taste,  and  hearing.  In  the  case  of  these  more  universal 
qualities,  the  part  which  the  mind  takes  in  the  process  of 
cognizing  them  as  belonging  to  the  objects  is  immediate  and 
automatic,  and,  as  Mr.  Sully  observes,  "  may  be  supposed  to 
answer  to  the  most  constant  and  therefore  the  most  deeply 
organized  connections  of  experience." 

The  third  step  in  the  advance  of  Perception  consists  in 
the  mental  grouping  of  objects  with  reference  to  their  quali- 
ties, as  when  we  associate  the  coolness,  taste,  &c.,  of  a 
particular  fruit  with  its  size,  form,  and  colour.  Here  the 
more  frequently  a  certain  class  of  qualities  has  been  con- 
joined with  another  class  in  past  experience,  the  more  readily 
or  automatically  is  the  perceptive  association  established ;  but 
m  cases  where  the  conjunction  of  qualities  has  not  been  so 
frequently  or  so  constantly  met  with  in  past  experience,  we 
are  able  by  reflection  to  recognize  the  perceptive  association 
"as  a  kind  of  intellectual  working  up  of  the  materials 
supplied  us  by  the  past." 

A  further  development  of  the  perceptive  faculty  is  re- 
quired to  meet  cases  in  which  the  qualities  of  objects  have 
become  too  numerous  or  complex  to  be  all  perceived  simulta- 
neously. In  meeting  such  cases  the  faculty  in  question, 
while  perceiving  some  of  the  qualities  through  sensation! 
supplements  the  immediate  information  so  derived  with 
information  derived  from  previously  formed  knowledge ;  the 
qualities  which  are  not  recognized  immediately  through' sen- 
sation are  inferred.  Thus,  in  my  perception  of  a  closed  book 
I  have  no  doubt  that  the  covers  are  filled  with  a  number  of 
printed  pages,  although  none  of  these  pages  are  actually 
objects  of  present  sensation.  Or,  if  I  hear  a  savage  growl,  I 
immediately  infer  the  presence  of  an  object  presenting  so 
complex  a  group  of  unseen  qualities  as  are  collectively  com- 
prised in  a  dangerous  dog.  In  a  later  chapter  I  shall  have  to 
dwell  more  minutely  on  this,  which  I  may  term  the  inferential 
stage  of  perception,  and  I  shall  therefore  not  deal  more  with 
it  at  present. 

It  will  be  evident  that  the  various  stages  which  I  have 
named  in  the  development  of  Perception  shade  into  one 
another,  so  as  not  really  to  be  distinguishable  as  separata 


1 

) 

1 

L 

1 

i 

j 


PERCEPTION. 


129 


Btages ;  tliey  constitute  rather  one  uniforni  growth  on  which, 
as  in  the  case  of  Memory,  I  have  arbitrarily  marked  these 
several  grades  of  evolution.     Moreover,  it  will   be   evident 
that  the  term  "  Perception "  is  really  a  very  wide  one,  and 
may  be  said  to  cover  the  whole  area  of  psychology,  from  the 
confines  of  an  almost  unfelt  sensation  up  to  the  recognition 
of   an  obscure  truth  in  science  or  philosophy.      On  this 
account  the  term  has  been  condemned  by  some  psychologists 
as  too  extensive  in  its  application  to  be  distinctive  of  "any 
particular  faculty ;  but  nevertheless  it  is  clearly  impossible  to 
do  without  it,  and  if  we  are  careful  to  remember  tlie  sense  in 
which  we  employ  it— whether  with  reference  to  the  lower  or 
to  the  higher  faculties  of  mind— no  harm  can  arise  from  its  use. 
I  have  just  said  that  in  the  highest  stage  of  its  develop^ 
ment  Perception  involves  Inference ;  and  I  have  previously 
said  that  in  its  lowest  stages  it  involves  Memory.     I  must 
now  point  out  more  particularly  that  in  its  ascending  stages 
Perception  involves  Memory  of  ascending  sta<jes.     Thus  the 
perception  shown  by  a  new-born   infant  of  sweet  tastes  as 
distinguished  from   sour  tastes  and  the   rest,  implies  the 
presence  of  that  lowest  stage  of  memory  which  we  have  seen 
to  consist  in  cognizing  a  present  sensation  as  like  a  past  sen- 
sation.    Again,  the  power  of  discerning  a  change  of  milk 
implies  the  power  of  cognizing  a  present  sensation  as  unlike 
a  past  sensation.     Next,  when  memory  advances  to  the  stage 
of  associating  ideas  by  contiguity,  perception  also  advances 
to  the  stage  of  re-cognizing  objects  with  their  qualities  and 
relatic  s  of  coexistence  and  sequence.     This  in  turn  leads  to 
the  power  of  recognizing  objects,  qualities,  and  relations  by 
similarity— the  power  on  which  we  have  seen  the  next  phase 
of  memory  to  depend.     And,  lastly,  from  this  point  onwards 
perception  throughout  depends  exclusively  upon  the  associa- 
tion  of  ideas,  no  matter  how  elaborate  or  refined    such 
association  may  become. 

The  fact  that  perception  is  thus  everywhere  and  indis- 
solubly  bound  up  with  memory,  is  an  important  fact  to  be 
clear  about ;  for  when  memory  becomes  so  liabitual  as  to  be 
virtually  automatic  or  unconscious,  we  are  apt  to  lose  sight  of 
the  connection  between  it  and  perception.  Thus,  a?  Mr. 
Spencer  observes,  we  do  not  speak  of  remembering  that  the 
sun  shines ;  yet  we  speak  of  perceiving  that  the  sun  shines. 
As  a  matter  of  fact,  however,  we  do  remember  that  tlie  sun 


I    .    !!>* 


11 
.111 


- 1 


i 

t 


130 


MENTAL  EVOLUTION  IN  ANIMALS. 


H  ■  I 


I'l  : 


'7 


slimes,  and  in  all  the  habitual  phenomena  of  experience  such 
memories  as  tliis  become  so  blended  with  our  perceptions  of 
the  phenomena  that  the  memories  may  be  said  to  form 
intef^ral  parts  of  the  perceptions.  Suppose,  for  instance,  we 
see  a  man  whose  face  we  know,  but  cannot  remember  who 
the  man  is.  Here  the  perception  tliat  the  object  which  we 
see  IS  a  man,  and  not  any  other  of  the  innumerable  objerts  in 
Nature,  is  so  intimately  bound  up  wit'-  •<'!  organized 
association  of  ideas,  that  we  do  not  thiin-  .3  perception 

thus  far  as  really  depending  on  memory.  L  .0  only  wh:n  we 
turn  to  tlie  incompletely  organized  association  of  ideas 
between  the  particular  face  and  the  particular  individual, 
that  we  recognize  the  incompleteness  of  this  part  of  the 
perception  to  depend  upon  the  incompleteness  of  memory. 

Now  these  considerations,  obvious   though  they  appear, 
constitute  the  first  stage  in  a  disagreement  on  an  important 
matter  of  principle,  which  will  become  more  pronounced  when 
I  have  to  deal  with  the  higher  faculties  of  mind,  and  which,  I 
regret  to  say,  has  reference  to  the  writings  of  Mr.  Spencer.    In 
Ins  chapter  on  Memory  Mr.  Spencer  takes  the  view  that,  so  long 
as  "  psychical  changes  are  completely  automatic,  memory,  as 
we  understand  it,  cannot  exist— there  cannot  exist  these 
irregular  psychical  changes  seen  in  the  association  of  ideas." 
Now,  I  have  already  given  my  reasons  for  nob  restricting  the 
term  Memory  to  the  association  of  ideas ;  but,  passing  over 
this  point,  I  cannot  agree  that  if  psychical  changes  (as  dis- 
tmguished  from  physiological  changes;  are  completely  auto- 
matic, they  are  on  this  account  precluded  from  being  regarded 
as  mnemonic.     Because  I  have  so  often  seen  the  sun  shine, 
that  my  memory  of  it,  as  shining,  has  become  automatic,  I 
see  no  reason  why  my  memory  of  this  fact,  simply  on  account 
ot  Its  perfection,  should  be  called  no-memory.   And  similarly 
with    all   those  well-organized  memories  which  constitute 
integral  parts  of  perceptions.     In  so  far  as  they  involve  true 
"  psychological  changes,"  and  therefore  imply  the  presence  of 
conscious  rccogmtion  as  distinguished  from  reflex  action,  so  far, 
I  think,  no  line  of  demarcation  should  be  drawn  between 
them  and  any  less  perfect  memories.     I  shall  recur  to  this 
point  when  I  come  to  consider  Mr.   Spencer's  views  on 
Instinct  and  Eeason. 

Another  point  wliich  we  have  here  to  consider  is  the  part 
which  heredity  has  played  iu  forming  the  perceptive  faculty 


PERCEPTIOIf. 


131 


of  the  individual  prior  to  its  own  experience.    We  have 
already  seen  that  heredity  plays  an  important  part  in  forming 
memory  of  ancestral  experiences,  and  thus  it  is  that  many 
animals  come  mto  the  world  with  their  powers  of  perception 
already  largely  developed.     This  is  shown  not  only  by  such 
cases  as  those  of  Galen's  kid,  and  Preyer's  chickens  before 
mentioned,   but  by  all  the  host  of  instincts  displayed  by 
newly-born  or  newly-hatched  animals,  both  Vertebrate  and 
Invertebrate.     This  subject  will  be  fully  considered  when  I 
come  to  treat  of  Instinct,  and  then  it  will  be  found  that  the 
wealth  of  ready-formed  information,  and  therefore  of  ready- 
made  powers  of  perception,  with  which  many  newly-born  or 
newly-hatched    animals  are   provided,   is  so  great  and  so 
precise,  that  it  scarcely  requires  to  be  supplemented  by  the 
subsequent  experience  of  the  individual.     In  different  classes 
of  animals  these  hereditary  endowments  vary  much  both  in 
kind  and  in  degree.     Thus,  with  mammals  as  a  class,  heredi- 
tary perception  has  reference  in  its  earliest  stages  to  the  senses 
of  smell  and  of  taste ;  for  while  many  mammals  are  born 
blmd,  some  probably  deaf,  and  all  certainly  very  deficient  in 
powers  of  locomotion,  they  invariably  show  more  or  less 
perceptive  powers  of  taste,  and  very  frequently  well-advanced 
perceptive  powers  of  smell.     This  we  have  already  seen  in 
the  case  of  Galen's  kid,  and  in  the  case  of  the  do*^  (whose 
ancestors  have  depended  so  largely  upon  the  perfection  of 
smell)  the  same  thing  occurs  in  so  high  a  degree,  that  so 
special  an  olfactory  impression  as  is  produced  by  the  odour  of 
a  cat  will  cause  a  Utter  of  newly-born  puppies  to  "  pulf  and 
spit."*  ^ 

Birds  come  into  the  world  with  better  endowments  of 
perception  than  animals  of  any  otlier  class.  For  they  are  in 
full  possession  of  every  sense  almost  immediately  after  they 
are  hatched,  and,  as  we  shall  see  later  on,  they  are  then  able 
to  use  their  senses  nearly  as  well  as  they  are  ever  eHe  to 
use  them. 

Reptiles  are  likewise  hatched  with  their  powers  of  percep- 
tion alniost  as  highly  developed  as  they  are  ever  destined  to 
become,T  and  the  same  as  a  rule  is  true  of  invertebrated 
animals. 

I  must  now  say  a  few  words  on  the  physiology  of  Percep- 

•  See  p.  164.  f  See  Animal  Intelligence,  pp.  256-7. 


.".J-l. 


,  m 


I  ( 


I   ;i 


.i   is 


n 


.11 

Ail  „ 


•Hi 

ill 

..^pllrf 

IllllfEd 

132 


MENTAL  EVOLUTION  IN  ANIMALS. 


If 


:nli 


I'H 


tion— -or,  more  correctly,  on  what  is  known  touching   the 
physiological  processes  which  accompany  Perception.    ° 

In  earlier  chapters  I  have  already  stated  that  the  only 
distinction  which  is  known  on  the  physiological  side  between 
a  nervous  activity  which  is  accompanied  by  consciousness, 
and  a  nervous  activity  which  is  not  so  accompanied,  consists 
m  a  difference  of  time.  I  shall  now  give  the  experimental 
data  on  which  the  statement  rests. 

Professor  Ex.ner  has  determined  the  time  which  is  occu- 
pied by  a  nerv(i-centre  of  man  in  executing  its  part  in  the 
performance  of  a  reflex  action.     That  is  to  say,  the  rate  of 
transmission  of  a  stimulus  along  a  nerve  beinf»  known,  and 
the  length  both  of  the  afferent  and  efferent  nerves  concerned 
in   a  particular  reflex    act  being   known,   as   also  is  the 
"period  of  latency  "  of  a  muscle  ;    the  time  occupied  by  the 
nerve-centre  in  conducting  its  operations  was  determined  by 
subtracting  the  time  occupied  by  the  passage  of  the  stimulus 
along  the  afferent  and  efferent  nerves,  plus  the   period   of 
latency  of  a  muscle,  from  the  total  time  between  the  fall  of 
the  stimulus  and  the  occurrence  of  the  muscular  contraction. 
This  time  was  found  in  the  case  of  the  reflex  closure  of  the 
eye-lid  to  vary  between   0-0471  and  0-0555  of  a  second 
according  to  the  strength  of  the  stimulus.*      By  a  similar 
process  Exner  has  estimated  the  time  required  for  the  central 
nervous  operations  which  are  together  comprised  in  having  a 
simple  sensation,  perceiving  the  sensation,  and  the  volitional 
act  of  signalling  the  perception.     That  is  to  say,  an  electrical 
shock  being  administered  to  one  hand,  and  as  quickly  as 
possible  signalled  by  the  other,  the  time  occupied  by  the 
nerve-centre  in  performing  its  part  of  the  process  was  esti- 
mated as  in  the  previous  case.     This  time  in  the  case  of  this 
experiment  was  found  to  be  00828",  which  is  nearly  twice  as 
long  as  that  which,  as  we  have  just  seen,  is  required  for  a 
nerve-centre  to  perform  its  part  in  a  reflex  action.f 

Acts  of  perception  in  which  different  senses  are  concerned 
occupy  different  times.  This  interesting  topic  has  been 
investigated  by  a  number  of  physiologists.^  According  to 
Bonders  the  total  "reaction-time"  (i.e.,  between  stimulus 
and  response)  is,  roughly  speaking,  for  touch  |,  for  hearing  ^, 

*  Arch./,  d.  ges.  Physiol.,  xliii,  526  (1874). 

t  Ibid.,  vii,  p.  610. 

X  See  Herman,  Eandb.  d.  Physiol,  Bd.  II,  Th.  2,  8.  264. 


PliRCErTION. 


133 


and  for  sight  ^  of  a  second  *  The  ohsei'vations  of  Von  Wit- 
tichf,  Vintschgau,  and  Honig-Schnied+ show  tliat  the  reaction- 
time  lor  taste  varies  between  0-1598"  to  0'23r)l"  according 
to  the  kind  of  taste ;  being  least  for  salt,  more  for  sugar,  and 
most  for  quinine.  A  constant  electrical  current  applied  to 
the  tongue  gives  a  reaction-time  for  the  resulting  gustatory 
impression  of  01 67".  I  am  not  aware  that  any  experiments 
have  been  made  with  regard  to  smell.  Exner  has  more 
minutely  determined  on  himself  the  reaction- time  for  touch, 
sound,  and  sight,  with  the  results  which  are  emlwdied  in  the 
following  table.  The  signal  was  in  all  cases  given  by  the 
right  hand  depressing  an  electrical  key  ; — 


Direct  electrical  stimulation  of  retina 
Electrical  shock  on  left  hand         . . 
Sudden  sound  . .         . . 

Electric  shock  on  forehead. . 
Electric  shock  on  right  hand 
"Visual  impression  from  electric  spark 
Electric  shock  on  toe  of  left  foot  . . 


01139" 

01276 

01300 

01370 

01390 

01506 

0-174ti§ 


It  is  thus  noticeable  that  although  the  sensation  of  light  pro- 
duced by  vision  of  an  electric  spark  is  much  greater  than 
that  produced  by  electrical  stimulation  of  the  optic  nerve, 
the  interval  between  the  stimulation  and  the  perception  is 
much  longer  in  the  former  case.  Seeing  that  the  optic  nerve 
is  so  short,  this  difference  cannot  be  attributed  to  the  time 
lost  in  transmission  along  the  nerve,  and  must  therefore  be 
supposed  due  to  the  time  rec^uired  for  the  nerve-endings  in 
the  retina  to  complete  all  the  changes  (whatever  they  may 
be)  in  which  their  response  to  luminous  stimulation  consists. 
Thus  in  the  case  of  hearing,  as  the  above  table  shows,  some- 
what less  time  is  consumed  in  the  whole  act  of  perception 
than  is  consumed  in  the  case  of  sight  by  the  peripheral 
changes  taking  place  in  the  retina. 

_  According  to  Helmholtz  and  Baxt,  the  more  complex  an 
object  of  visual  perception  is,  the  greater  must  be  tlie  dura- 
tion of  its  image  upon  the  retina,  in  order  that  the  perception 
may  be  made  ;  while,  within  certain  limits,  the  intensity  of 
the  image  does  not  affect  the  time  required  to  make  the  per- 

•  Arch.f.  Anat.  und  Physiol,  1868,  p,  657. 
t  Qt.  Set.  Med.  (3),  xxxi,  p.  113. 
J  Arch.f.  Anat.  und  Phi/siol.,  x,  p.  1. 
§  PJliiger'a  Archiv.,  Bd.'VII,  p.  620. 


I :   ' 


»   u 


S  ! 

'I       'I 
Ml       .  i 


I! 


1 1       4 


m  ■. 


:  ^!l::! 

]l' 

Mil 

134 


MENTAL  EVOLUTION  IN  ANIMALS. 


M    i 


accordingly.  The  sfate  of  ma  ter  thusTrese^^^^^^^^  f  hT "'.' 
IS  called  by  Bonders  a  "  Dilemma  "^nHf  if  fn  -^^^  .""'"^ 
table  of  results  ;—  -^^^mma,    and  the  following  is  his 

DUemma  of  hearing ,  t„„  Towele  .udd.nb  °Sed  •  'i„.I  V^       "" 
be  made  on  hearing  one  only  '  '    ^ "'  *** 

Dilemma  between  five  yoweU;,ig„alU  beta       "         ."I     JJ^ 

bet  Jt  te^oo^^^rArtirf •  ™'  ^."''^"'»  p^"-" 

required  Jr:;tf  mee^ng  f d-Uemmri^f '^  .'?^  J"»? 

o J'le^^rrr;  bf  I'rrdtrtr-^'^  ^ 

following  results  :--$  ^  ^  Auerbach,  with  the 

Jun*e,  m?-  *^-  ''•  ^''-  -^'^^''''•'  ^**- 1^'  P-  329;  Jfo«a..i«..  e^.  Ser.  Acad., 
pp.  657-5l''"'^"''  investigations,  see  ArcMv.  f.  Anat.  und  Pkysiol,  1868. 
t  Archiv.f.  d.  ges.  Fhysiol,  1877,  pp.  298-380. 


PERCEPTION. 

Locnlization  by  Bight 

UiHtinpjmshing  colour    . . 
Localization  by  hearing  (least  interval) 
l)i»tingui8hing  pitch  (high  notes)       . . 
Localization  by  touch   . . 
I)i8tinguiMhing  pitch  (low  note's) 
Localxzation  by  hearing  (greatest  interval) 


135 


0011*' 

0-01  a 

0-015 
0019 
0021 
0-034 
0062 


T.rJ!^  *  ff^^""  ^"'""^^^  °^  alternatives  are  allowed  bv  tho 

Ttrrfs^ir^^^^^^^^^^ '  '''^^'-'"^^^  -^-^  ^ « 

car.^'^  ^^^^  required  for  perception  in  the  case  of  all  tli« 
''Zl2rL:lni^^^^^^  ^"^'  underthe' name'o 

aickness,and  sundry  Ss  of  Sfu^s     "EltTt^  ^/"^^  °^ 

people  of  less  vigorous  or  lively  temperaments  Accoid^n! 
to  Exner  persons  who  are  accustomed  to  aUow  theh^Tde.,^! 
run  slipshod  are  relatively  slow  in  forming  thdrpertptJons  or 
spondiL  r  '  ^T'  T''''^'"^'  ^^^"^-  rece'fvhi'rd're: 
show  tTp  ^i^  '^™''^-'-  J^^  ^^^'  ^^^  following'table  to 
vdTals      *    ^'''"''  ""  ^^'    reaction-time  of  seven  hi61. 


Age. 


26 
23 


Beaction-time. 


0  1337 
0  -3311 


76 

0-9952 

24 

0  1751 

20 

0  -2562 

22 

0  1295 

85 

0  1381 

Remarks. 


Rough,  lively  labouring-man. 

S/''  ™°''^°'^°*«'  ^"*  '^tlier  slow  in  apprehen- 
Infirm  and  not  intelligent. 
Slow  and  deliberate  in  movements, 
blow  and  somewhat  uncertain  in  movements 
blow  and  very  precise  in  movements. 
Accustomed  to  manual  work. 


Concerning  the  effects  of  drugs  it  is  enou-h  to  sav  thaf 
Exner  found  two  bottles  of  Shine-wine  increased  hs  react  on 

WftjJe   shooting  that  an  amount  of  alcohol   not  sufficient 

tr£^'C/-T'''^'t^iy'^'''^  ^^^^t«'i«  apt  to  make 
one  shoot  behind  one's  birds.     And  here,  with  reference 

to  the  personal  equation,  I  may  briefly  'aUude  t^  some 

m     r  


•  Zoc.  cit.,  p.  612. 


t  Loc,  cit.,  p.  628. 


II 


III 


-•  r      1 


!    li 


- ,- 

i  ^.1 

i : ;  1 

\ 

;  i 

■  {     ] 

,     ''; 

186 


MENTAL  EVOLUTION  IN  ANIMALS. 


I   I 


hitherto  iininiiaislu'd  observations  of  my  own,   which   has 
served  to  display  a  positively  astonishing  difierence  between 
(litterent  individuals  with  respect  to  tlie  rate  at  whicli  they 
are  able  to  read.       Of   course  reading  implies  enormously 
intricate  processes  of  perception  botli  of  the  sensuous  and  of 
the  mtelleotual  order;    but  if  we  choose  for  these  observa- 
tions persons  who  have  been  accustomed  to  read  much  we 
may  consi.ler  that  they  are  all  very  much  on  a  par  with 
respect  to  the  amount  of  practice  which  they  have  had,  so 
that  the  differences  in  their  rates  of  reading  may  fairly  be 
attributed  to  real  dillerences  in  their  rates  of  forming  com- 
plex  perceptions  in  rapid  succession,  and  not  to  any  merely 
accidental  difterences  arising  from  greater  or  less  facility 
acquired  by  special  practice.  ' 

My  experiments  consisted  in  marking  a  brief  printed 
paragrapli  m  a  boc\k  which  had  never  been  read  by  any  of 
the  persons  to  whom  it  was  to  be  presented.     The  pararrraph 
which   contained   simple   statements  of    simple   facts!  was 
marked  on  the  margin  with  pencil.      The  book  was  then 
placed  before  the  reader  open,  the  page  however  being  covered 
with  a  sheet  of  paper.      Having  pointed  out  to  the  reader 
upon  this  sheet  of  paper  what  part  of  the  underlying  pa^e 
the  marked  paragraph    occupied,  I  suddenly  removed  the 
sheet  of  paper  with  one  hand,  while  I  started  a  chronograph 
with  the  other     Twenty  seconds  being  allowed  for  reSdiU 
the  paragrapli  (ten  lines  octavo),  as  soon  as  the  time  was  up  I 
again  suddenly  placed  the  sheet  of  paper  over  the  printed 
page,  passed  the  book  on  to  the  next  reader,  and  repeated  the 
experiment  as   before.       Meanwhile   the   first  reader,   the 
moment  after  the  book  had  been  removed,  wrote  down  aU 

if  .1,     ?[  ^  '"^  ^""^^"^  remember  having  read.    And  so  on  with 
all  the  other  readers. 

Now  the  results  of  a  number  of  experiments  conducted  on 
this  method  were  to  show,  as  I  have  said,  astonishing  differ- 
ences m  themaximim  rate  of  reading  which  is  possible  to 
different  individuals,  aU  of  whom  have  been  accustomed  to 
extensive  reading.  That  is  to  say,  the  difference  may  amount 
to  4  to  1 ;  or,  otherwise  stated,  in  a  given  time  one  indi- 
vidual may  be  able  to  read  four  times  as  much  as  another. 
Moreover,  it  appeared  that  there  was  no  relationship  between 
slowness  ot  reading  and  power  of  assimilation ;  on  the  con- 
trary, when  all  the  efforts  are  directed  to  assimilating  aa 


'I  <l 


PERCEPTION. 


137 


mtich  fts  po.qsihlG  in  a  f^ven  time,  the  rapid  rentlera  (as  shown 
by  their  written  notes)  usually  give  a  better  account  of  the 
portions  of  the  paragraph  which  has  been  compassiul  by  the 
slow  readers  than  the  latter  are  able  to  give ;  and  the  most 
rapid  reader  whom  I  have  found  is  also  tlie  best  at  assimi- 
lating. I  should  further  say  that  there  is  no  relationship 
bei  veen  ra})idity  of  perception  as  thus  tested  and  intellectual 
activity  as  tested  by  the  general  results  of  intellectual  work ; 
for  I  have  tried  the  experiment  with  several  highly  dis- 
tinguished men  in  science  and  literature,  most  of  whom  I 
found  to  be  slow  readers.  Lastly,  it  is  worth  observing  that 
every  one  who  tries  this  experiment  finds  that  it  is  impossi- 
ble, with  any  amount  of  eflbrt  at  recollection,  to  remember, 
immediately  after  reading  the  paragraph,  all  the  ideas  which 
have  been  communicated  to  the  mind  l)y  the  paragraph.  But 
as  soon  as  the  paragraph  is  read  a  second  time,  the  forgotten 
ideas  are  instantly  recognized  as  having  been  present  to  the 
mind  while  reading.  This  shows  that  the  memory  of  a  full 
perception  may,  as  it  were,  be  immediately  crowded  out  by 
rapidly  succeeding  perceptions,  to  the  extent  of  being 
rendered  latent,  although  it  may  be  instantly  recalled  by  the 
recurrence  of  the  same  perception. 

So  much,  then,  to  show  that  the  personal  equation  in 
different  individuals  varies  the  more  the  greater  the  number 
and  the  higher  the  intricacy  of  the  perceptions  which  are  to 
be  made  in  a  given  time.  I  must  now  say  a  few  words  to 
show  that  the  personal  equation  in  the  same  individual 
admits  of  being  greatly  reduced  by  practice  in  making  par- 
ticular perceptions.  This  is  well  known  to  astronomers  so 
far  as  simple  acts  of  perception  are  concerned,  and  in  all  the 
researches  above  mentioned  touching  the  time-measurements 
of  simple  perceptions,  the  experimenters  found  that  practice 
had  the  effect  of  reducing  the  reaction-time.  The  degree  of 
reduction  which  might  thus  be  produced  was  itself  made  the 
subject  of  experiment  by  Exner,  who  chose  the  old  man 
already  mentioned  in  one  of  the  above  quoted  taWes  as  having 
the  unusuallv  long  reaction-time  of  09952".  After  a  little 
more  than  six  months'  practice  at  the  rapid  signalling  of  an 
electric  shock,  the  old  man's  reaction-time  was  reduced  to 
0-1866". 

This  universal  fact  of  repetition  serving  greatly  to  reduce 
the  physiological  time  required  for  the  performance  of  phy- 


A 


i         M 


i' 

1 

1 

m 

;          f;: ,                      ' 

i 


; 


, '  ' 

: ! .'  1 

i          • 

II 

i 
•     !  ■ 

i. 

m  X 


138 


MENTAL  EVOLUTION  IN  ANIMALS. 


! 


I  '    •■ 


[Ik 

m 

■■■II  f 

FIP 

^H; 

: 

1        1 

;  1 

* 

Li 

k  A  1 

glance,  that  hi/faThL^d^^^eliTJ  i° -"S  St  "'  ' 
women  araruTwo!      ^  ?^^  "^^  Perception,  observes  that 

that  lad^,  nSi^  ^oa'^'S  tt  pa^r '  "'"^  *^  ^'''' 

that'te'';.!rn-«t%*ratriT„f^''"''"^''^''^^'^y 
cateH  thfiT,  ,-f  ,-o  '       ^  general  rule,  less  aiuons  edu- 

I  have  dwelt  thus  at  length  on  all  the  main  facts  which 


PERCEPTION. 


139 


are  at  prese.it  known  concerning  the  time-relations  observ- 
able m  Pen  eption,  because  with  reference  to  the  theory  of 
the  rise  of  consciousness,  and  also  of  the  physiological  side 
of  mental  evolution  in  general,  these  facts  are  of  the  highest 
importance.      They  prove  by  actual  measurement  that  the 
simplest  psychical  actions  are  slow  as  compared  with  reflex 
actions,  that  they  can  be  rendered  more  rapid  by  practice, 
but  that  they  can  never  be  brought  to  be  so  rapid  as  reflex 
actions.     We  have  a  further  exemplification  of  the  effects  of 
practice  in  thus  quickening  the  act  of  perception  in  the 
higher  stages  of  the  process.    For  universally  the  effect  of 
previous  acts  of  perception  is  that  of  placing  the  mind  in 
readiness,  as  it  were,  for  performing  acts  of  the  same  kind. 
Ihe  mental  attitude  as  regards  these  particular  acts  of  per- 
cejDtion  is  then  the  attitude  of  what  Lewes   appropriately 
called  pre-perception  *     When  the  pre-perceptive  stage  is 
well  established,  the  memory,  or  the  memory  and  inference 
as  the  case  may  be,  arise  in  or  together  with  the  act  of  per- 
ception, so  forming  an  integral  part  of  the  act.     It  is  owing 
to  the  want  of  special  experiences  that  young  children  are  so 
slow  m  forming  perceptions  of  more  than  the  lowest  degree  of 
complexity;  as  Mr.  Spencer  observes,  they  take  a  long  time 
to  "integrate"  a  strange  face  or  other  unfamiliar  object;  and 
this,  otherwise  stated,  means  that  their  mental  attitude  of 
pre-perception  has  not  yet  been  fully  attained  for  such  and 
such  classes  of  objects ;  the  processes  of  memory,  classifica- 
tion, and  inference  do  not  occur  immediately  in  the  act  of 
perception,  and  therefore  the  full  mental  interpretation  of  the 
object  perceived  is  only  arrived  at  by  decrees.     Similarly  in 
adult  life  the  powers  of  perception  may  be  trained  to  a  mar- 
vellous extent  in  special  lines  by  practice,  as  we  have  already 
seen  m  the  example  of  Houdin's  son,  and  as  we  may  also  see 
m  the  fact  that  an  "  artist  sees  details  where  to  other  eyes 
there  is  a  vague  or  confused  mass."    1:he  influence  of  per- 
sistent attention  is  the  most  important  of  all  influences  in 
developing  the  rapidity  and   accuracy   of    the    perceptive 
powers  m  which  their  highest  excellence  -consists. 

We  have  now  to  consider  the  important  question  whether 

•  Problems  of  Life  and  Mind,  3rd  ser.,  p.  107.     See  also  Dr.  J  Hush- 
Lngs^Jackson  in  Brum,  Isos.  Ill  and  IV ;  and  Mr.  Su%,  in  lUmions,  pp. 


I  -.1 


'  .1;' 


f  !     f 


i.    ; : 


.  i 


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4 


140 


MENTAL  EVOLUTION  IN  ANIMALS. 


I'M 


t'S 


M 


Perception  arises  out  of  Eeflex  Action,  Eeflex  Action  out  of 
Perception,  or  whether  there  is  any  genetic  continuity  be- 
tween the  two  at  all.  This  is  a  most  difficult  question,  and 
one  which  I  do  not  think  we  are  as  yet  entitled  to  answer 
with  any  kind  of  scientific  confidence. 

According  to  Mr.  Spencer  the  perceptive  faculties  arise 
out  of  the  reflex  when  these  attain  a  certain  level  of  intricacy 
in  their  structure,  or  a  certain  degree  of  rarity  in  their  occur- 
rence.    Thus  he  says,  "  When,  as  a  consequence  of  advancmg 
complexity  and  decreasing  frequency  in  the  groups  of  external 
relations  responded  to,  there  arise  groups  of  internal  relations 
which  are  imperfectly  organized  and  fall  short  of  automatic 
regularity ;  then,  what  we  call  Memory,  becomes  nascent,"* 
But  as  a  matter  of  fact  it  seems,  I  think,  very  questionable 
whether  the  only  factors  which  lead  to  the  differentiating  of 
psychical  nervous  processes  from  reflex  nervous  processes 
are  thus  complexity  of  operation  combined  with  infrequency 
of  occurrence.     For  it  is  obvious  that  in  ourselves  certain 
truly  reflex  actions  are  of  immense  intricacy  and  of  exceed- 
ingly rare  occurrence — such,  for  example,  as  vomiting  and 
parturition.     The  truth  is  that,  so  far  as  definite  knowledge 
entitles  us  to  say  anything,  the  only  constant  physiological 
difference  between  a  nervous  process  accompanied  by  con- 
sciousness and  a  nervous  process  not  so  accompanied,  is  that 
of  time.      In  very  many  cases,  no  doubt,  this  difference  may 
be  caused  by  the  intricacy  or  by  the  novelty  of  the  nervous 
process  which  is  accompanied  by  consciousness ;  but,  for  the 
reason  which  I  have  given,  I  do  not  think  we  are  justified  in 
concluding  that  these  are  the  only  factors,  although  I  have 
no  doubt  that  they  are  highly  important  factors.     For  all 
that  we  know  to  the  contrary,  natural  selection  or  other 
causes  may  have  determined  the  physiological  conditions 
necessary  to  the  rise  of  consciousness  (and  so  to  the  perception 
of  pleasure  and  pain),  without  any  question  as  to  intricacy 
or  infrequency  being  concerned;  in  which  case  the  time- 
relations  needed  to  meet  these  conditions  would  have  become 
evolved  together  with  them.    And  I  think  it  speaks  in  favour 
of  some  such  view  as  this  that  the  structure  of  the  cerebral 
hemispheres  is  in  some  respects  strikingly  unlike  the  structure 
of  the  reflex  centres. 

Be  the  factors  what  they  may,  however,  it  is  a  great 

•  Principles  of  Fsi/chology,  vol.  i,  p.  446. 


PERCEPTION. 


141 


matter  to  have  the  sure  ground  of  experiment  on  which  to 
rest  the  fact  that  universally  psychical  processes  represent 
comparative  delay  of  ganglionic  action.     For  from  this  fact 
the  obvious  deduction  is,  as  stated  in  a  previous  chapter 
tliat  psychical  processes  constitute  the  subjective  expression 
of  objective  turmoil  among  molecular  forces ;   reflex  action 
may  be  regarded  as  the  rapid  movement  of  a  well-oiled 
machine,  consciousness  is  the  heat  evolved  by  the  internal 
friction  of  some  other  machine,  and  psychical  processes  as  the 
hght  which  IS  given  out  when  such  heat  rises  to  redness. 
Presumably,  therefore,  psychical  processes  arise  with  a  vivid- 
ness and  intricacy  proportional  to  the  amount  of  ganglionic 
friction— as,  indeed,  appears  to  be  experimentally  proved  by 
the  observations  of  Bonders  before  described.      Now  it  is 
certain  that  by  frequency  of  repetition,— i.e.,  by  practice  in  the 
performance  of  any  particular  psychical  act— the  amount  of 
this  ganglionic  friction  admits  of  being  lessened  (as  shown 
by  the  time  required  for  the  ganglionic  action  being  reduced), 
and  that  concurrently  with  this  change  on  the  objective  side 
of  matters,  a  change  takes  place  on  the  subjective,  in  that  the 
action   which  was   previously  conscious   tends   to   become 
automatic. 

Now  from  these  considerations  I  think  the  inference 
would  appear  to  be,  that  reflex  action  and  perception  probably 
advance  together— each  stage  in  the  development  of  the  one 
serving  as  the  groundwork  for  the  next  stage  in  the  develop- 
ment of  the  other.  And  in  corroboration  of  this  view  is  the 
general  fact,  that  throughout  the  animal  kingdom  there  is  a 
pretty  constant  correspondence  between  the  complexity  of 
the  reflex  actions  presented  by  an  organism  and  the  level  of 
its  psychical  development. 


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142 


MENTAL  EVOLUTION  IN  ANIMALS. 


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CHAPTER  X 

Imagination. 

We  have  already  considered  the  psychology  of  Ideation  to 
the  extent  of  defining  the  sense  in  which  I  employ  the  word 
"  Idea"  or  "  Image,"  and  also  to  the  extent  of  tracing,  both  on 
the  side  of  physiology  and  on  that  of  psychology,  the  prin- 
ciple of  the  association  of  ideas*  We  have  now  to  analyze 
the  psychology  of  Ideation  somewhat  more  in  detail. 

The  simplest  case  of  an  idea  is  the  memory  of  a  sensa- 
tion. That  a  sensation  may  be  remembered  even  when  there 
has  been  no  perception  is  proved,  not  only  by  the  fact  before 
mentioned  that  an  infant  only  a  day  or  two  old  can  distin- 
guish a  change  of  milk,  but  also  by  the  fact,  which  must  be 
familiar  to  all,  that  several  minutes  after  an  unperceived 
sensation  is  past,  we  are  able  by  reflection  to  remember  that 
we  have  had  the  sensation.  For  example,  a  man  reading  a 
book  may  hear  a  clock  strike  from  one  to  five  strokes  (or 
perhaps  more)  without  perceiving  the  sound,  yet  a  minute  or 
two  afterwards  he  can  recall  the  past  sensation  and  tell  the 
number  of  strokes  which  have  occurred.  And  in  simpler 
instances  the  memory  of  a  sensation  may  extend  over  a  much 
longer  time. 

The  simplest  case  of  an  idea,  then,  being  the  memory  of  a 
past  sensation  (as  distinguislied  from  the  memory  of  a  past 
perception),  it  follows  that  the  earliest  stages  of  ideation 
must  be  held  to  correspond  with  those  earlier  stages  of 
memory  which  we  have  already  described,  wherein  as  yet 
there  is  no  association  of  ideas,  but  merely  a  perception  of 
a  present  sensation  as  like  or  unlike  a  past  one.  Hence 
in  its  most  elementary  form  an  idea  may  be  said  to  consist 
in  the  faint  revival  of  a  sensation.  Tliis  view  has  already 
been  advanced  with  much  clearness  by  Mr.  Spencer,  Professor 

•  Sje  ChcipLers  II  and  III, 


K.. 


■II 


IMAGINATION. 


143 


past  sedation  is  thTZelrHndTnTr'"^^''''' '"«"  "^  « 
degree  of  intensity,  as  ™s  the  CMebml  1 ""''  *?"l''  ""'  '■» 
panied  the  origin  J  sensatfcn*  ""«''  *'""'»  '"='>°"'. 

gar/^d  t  thfmXVnlS"'  "^f""  ^^  ^  - 
diately  after  this  the^rtacfnW?  Perception,  and  imme- 
comes  in.  Later  on  thZ^  ■  '"^"".""■"n  by  contiguity 
and  from  tht  point  oSdsMlr""''/"''  ^^  """""'y^ 
tion.  generalizat^oranr^mMctn"  tr^^^^^^^^^  '^  '''""^ 
degrees  which  will  constitCone  Tthe  tZc,' M?  '^"'^ 
sidered  in  my  next  work  ^      *"  **  ^o- 

alreaXmStedlhelfwest'r  "  1't  i"^  ^'^^  *»'  "«  h*™ 

of  MeLry  andCltciat S^  Ide^^'Tes::'-^  'T'"^ 
(ore,  the  analysis  at  the  noint  whsr,  „  ;i,  ^e™™"&  Uiere- 
devote  this  chapter  to  a  cmsMm?SnTf  ^'""  i'^', '''  ^  =•>"" 
of  the  idea-forming  powers  Shi  '"""  '"S'"'"'  Ph^'^es 
elude  under  the  gen'erTlte™  t'^^^LT^  "™^^"™''^'  ""- 

menW  ^taTe  rVhiSiThifdl  7  '"^'"t^  »  ™"^'y  «« 

xxc&t^SSr'r---^^^^^ 

of  the  origiUlLp'rTSnT' ."  TW^rfiira  nT^'f',  ^"^  ^^''^^  -P««tion 
Tivid  order,  and  then,  afterwards,  there  mafc^ff''*''^  manifestetiorof  the 
that  18  hke  It  except  in  being  much  ImlTtinT"     JT'l^l^"^  manifestation 
And  Professor  Bain  says,  "  What  is  thp  n,«n         *     ^^""^^  Principles,  p.  145  ) 
a  resusdtated  feeling  Jf 'resVstonce  a  snTelf  o^n  "''"^f  °"  ""^'^^  ^^  with 
answer  that  seems  admissible.     Ser'S/^.!/- *"""'*  ^     ^^^'^  '«  "'^Jy  one 
i'ar^,,  and  in  the  same  manner,  astheoTotSn-  '''"^^'*  *^'  "^''^  *«'«« 
''°^.  ^n  am,  other  assignable  manner"    (^l^f^'  "'"^  «"  other  parts 
qmte  assenting  to  thif  view  of  ideation  io  f ^  Z\t*'''''*^  P"  ^3«)     Wl,ile 
ject  18  concerned,  I  think  we  aSfir  too  i.nn      .P'^/^°^°8^  °*' ^^^^  «'''b. 
cerebration  to  indulge  in  any  such  confid.S     'S"°.''^°^  o^  the  physiology  of 
seat  and  manner  of  the  f«L  ofldet'"  A^"°'  'TJ'="°^  ^^«  ?>---« 
Spencer's  views,  it  is  needless  to  repeat  the  nn,^f-"'  ^^%^^^^^^r,^^^  Mr. 
him  touching  the  earliest  stages  of  memorv    ^r  M  '°  T.^i"''  '  ^''''^^^^  'vith 
the  association  of  ideas.     Only  I  may  pS^?  fl    .'"  ^f^°"°  *^«  ^^^v.  nt  of 
Idea  IS  held  to  consist  in  a  faint  revSf of  !  seLn  ,V  //'  "'^^  ''^"^^^'^  P°««iblo 
a  perception),  it  follows  that  the  occurrence  of  /h     ^^'  ^^r^inguished  from 
precedes  the  occurrence  of  its  assSirwin/f       ".uP^"'*  P^^^'^le  idea 
the  wemory  of  the  sensation    or  t^«  +■    T       •     f^^  °*'^''''  idea;  and  if  so 
the  idea  is'held  to  eons  st  must  also  n^.  '"^'^^^  "^  "^«  ^'-"n^^tion  in  whic?a 
revivttls  of  the  same  kind!'  ^'''"^'  ''''^  association  with  other  fS 


.1  ,.' 


ii!    !'fi 


•1.1' 


144 


MENTAL  EVOLUTION  IN  ANIMALS. 


i 


u 


I'l  I  (1 ' 


taken  to  mean  the  highest  development  of  the  faculty  in  the 
intentional  imaging  of  past  impressions.  In  this  sense  we 
speak  of  the  imaginations  of  the  poet,  imaginations  of  the 
heart,  scientific  use  of  the  imagination,  and  so  on ;  in  all  of 
which  cases  we  presuppose  the  powers  of  high  abstraction  as 
well  as  tliose  of  intentional  ideal  combinations  of  former 
actual  impi  I  ssions.  It  is  needless  to  say  that  even  in  man, 
long  before  the  faculty  in  question  attains  to  this  degree  of 
development,  it  occurs  in  lower  degrees.  Indeed,  this 
highest  degree  may  be  said  to  bear  the  same  relation  to  the 
lower  degrees  that  recollection  bears  to  memory ;  it  implies 
the  introspective  searching  of  the  mind  with  the  conscious 
purpose  of  forming  an  ideal  structure.  But  just  as  recollec- 
tion is  preceded  by  memory,  or  the  power  of  intentional 
association  by  that  of  sensuous  association,  so  is  imagination 
of  the  intentional  kind  preceded  by  imagination  of  the 
sensuous. 

After  considering  the  subject  I  think  we  may,  for  the 
purposes  of  analysis,  conveniently  divide  the  grades  of 
Imagination  into  four  classes : — 

1.  On  seeing  any  object,  such  as  an  orange,  we  are  at 
once  re-minded  of  the  taste  of  an  orange — have  an  imagina- 
tion of  that  taste  ;  and  this  is  called  up  by  the  force  of  mere 
sensuous  association.  This  is  the  lowest  stage  of  mental 
imagery. 

2.  Next  we  have  the  stage  in  which  we  form  a  mental 
picture  of  an  absent  object  suggested  to  us  by  some  other 
object,  as  when  water  may  suggest  to  us  the  idea  of  wine. 

3.  At  a  still  higher  stage  we  may  form  an  idea  indepen- 
dently of  any  obvious  suggestion  from  without,  as  when  a 
lover  thinks  of  his  mistress  even  in  spite  of  external  dis- 
tractions ;  the  course  of  ideation  is  here  self-sustained,  and 
no  longer  dependent  for  its  mind-pictures  (ideas)  upon  the 
suggestions  of  immediate  sense-perceptions.  At  this  stage 
we  have  dreaming  in  sleep,  where  the  course  of  ideation  runs 
on  in  a  continuous  stream  when  all  the  channels  of  sense  are 
closed. 

4.  Lastly  we  have  the  stage  of  intentionally  formirg 
mind-pictures  with  the  set  purpose  of  obtaining  new  ideal 
combinations. 

Such  being  the  great  differences  in  the  degrees  to  which 
the  faculty  of  Imagination  may  attain,  I  have  made  the 


\l 


IMAGINATION.  i^k 

,  145 

the  origin  of  PefleSr  Of  1.  .?  '^^'°'''  ^"^  ^^^^^d 
mates  are  intended  here  as  p1.  '^  ^^''!  comparative  esti- 
with  some  rouX  approx'i'ni  T^f ?'  *°  '^'^''^^  °^«^ely 
relative  amount  o^aSmt  on  ^  ^^'  ^/^^^^^  *^«th  the 
mental  species  wh  ch  weTenomiL^^^^^^^^^  T^  ^^  ^^e 

indeed,  as  I  have  said  ^£0^?^^  \  i.^'"^*'"'-.  ^  ^^^^^^^r 
selves  of  an  artificial  or  Innt'  .^  ?^'f  'P^^'^«  ^^^  them- 
we  call  facultLstrlTr^^^^^^^^^^  character-that  what 

than  objective  or  indenenden?  Lf  iT  °^^,"^aking  rather 
the   classification  of  tCe  f!cSf  k'''  ^^^.^herefore  thau 
deserves  in  some  remote  sense  to  t    ^  Py^>^^«gi«ts  only 
one.     Still  it  is    thTbest  cLlf ''^^'^'^,  "^  ^  ^^^"ral 
purpose  of  comparing  onf  grtde  ff^.r^^"^^^  ^''  '^^ 
another,  and  there  can  be  no  hari  T^I    k'^"'^°^  ^''^ 
remember,  what  I  desire  alwo v.  flv.        ^^^P^^^^g  it  if  we 
representative  tree  is  des3  n.l  ^^^^"^J^^bered,  that  my 
relation  between  the  faculties  o?-'  ^       ^^"^  *^'  ^""^'^^ 
formulated  by  psycholoS    '  ^'  *^'''  ^^^^  ^^^^ 

reql^e  ::^Z^ ^^  TetelfaV^  7^T^^^^  ^^ 
tion  as  attaining  to  the  same  S  !1  .1,^  '^P®''  °^  Imagina- 
for  psychologists  mt  h    natSv    nf/ T^^ '^  "^^^^^^^^^^ 
that  I^am  inadvertenti;  Tntr^^.    h  "docrne^S  ReT  '' 
'owever,  is  not  the  case.  %n.  i?w"l  1  ^.^^1^«°»- 


that,  if  we  were  able  tn   1;      •    ■^^''  ^^^^^^S^  ^^  is  true 

would  become  thf  only  rS^^^^^^^^^  't'^?'''''^"'  ^'^^^^^ 
diagram  to  favour  any  sV£rd  a  Z7'  ^  ?'  "°^  ^^^^""^  '^^ 
when  I  shall  have  occasion  To  pt.T  •    "^l  ^^  .^7  next  work, 

of  the  representative  tSelwillTpr*^'  ^'^^''  ^^^^^h«« 
do  not    intend  Abstr7c  ion    ^  .Sf  apparent  that,  as  I 

I  pK^P^n^aTv^^^^^^^^^^^^^  ^^.  Win  be  seen  that 

Mollusca.  Insecta,  Arrchnida    Cri,!'"''^!"'''^  ^^^  «^^«««« 

bef.und,a3in:ti:^ef2^ir«SS^-^^^^^ 


In 


146 


MENTAL  EVOLUTION  IN  ANIMALS. 


mil 


iiv 


i '    F 


1|M:, 


the  octopus  which  followed  a  lobster  with  which  it  had  been 
fighting  into  an  adjacent  tank,  by  labcriously  climbing  up 
the  perpendicular  partition  between  the  two  tanks,  must 
have  been  actuated  by  an  abiding  mental  image,  or  memory, 
of  its  antagonist ;  the  spiders  which  attach  stones  to  their 
webs  to  hold  them  steady  during  gales  must  similarly  be 
actuated  by  a  faculty  of  Imagination ;  and  the  same  is  no 
less  true  of  the  crab  which,  when  a  stone  was  rolled  into  its 
/  burrow,  removed  other  stones  near  its  margin  lest  they 
should  roll  in  likewise.  The  limpet  which  returns  to  its 
home  after  a  browsing  excursion,  must  have  some  dim 
memory  or  mental  image  of  the  place. 

So  much,  then,  for  proof  of  Imagination  of  the  first 
degree.  Imagination  of  the  second  degree — or  that  wherein 
one  object  or  set  of  circumstances  suggests  another  and 
similar  object  or  set  of  circumstances,  occurs  first,  so  far  as 
my  evidence  goes,  among  the  Hymenoptera.  But  here  the 
cases  of  an  association  of  ideas  leading  to  the  establishment 
of  a  mental  imagery  more  or  less  remote  from  the  immediate 
circumstances  of  perception  are  much  too  numerous  to 
quote.  I  shall  therefore  merely  refer  to  the  headings 
"  General  Intelligence "  in  the  chapters  on  Ants,  Bees,  and 
Wasps.*  Among  the  higher  animals  imagination  of  this 
grade  is  of  frequent  occurrence  and  strong  force.  Thus,  to 
supply  only  one  example,  Thompson,  in  his  "  Passions  of 
Animals  "  (p.  59),  gives  the  case  of  a  dog  "  which  refused 
dry  bread,  and  was  in  the  habit  of  receiving  from  his  master 
little  morsels  dipped  in  gravy  of  the  meat  remaining  in  the 
plate,  snapped  eagerly  after  dry  bread  if  he  saw  it  rubbed 
round  the  plate,  and  as,  by  way  of  experiment,  this  was  re- 
peatedly done  till  its  hunger  was  satisfied,  it  is  evident  that 
the  imagination  of  the  animal  conquered  for  the  time  its 
faculties  of  smell  and  taste." 

To  tins  order  of  imagination  also  belongs  the  wariness  of 
wild  animals.  Thus  Leroy,  who  in  his  capacity  of  Eanger 
had  a  laige  experience,  says,  "  In  the  first  hours  of  the  night, 
when  th(}  countenance  of  darkness  is  in  itself  a  fertUe  source 
of  hope  to  the  fox,  the  distant  yelping  of  a  dog  will  check 
him  in  the  midst  of  his  career.  All  the  dangers  which  he 
has  on  various  occasions  passed  through  rise  before  him  ;  but 
at  dawn  this  extreme  timidity  is  overborne  by  the  calls  of 

•  Animal  Intelligence,  pp.  122-40,  and  181-19. 


IMAGINATION. 


147 


appetite;  the  animal  then  becomes  bold  by  necessity     He 
even  runs  to   mftfif.  Hnnaot.    t»,«,„; —  r.- ./  i-^        ./'     . 


even  runs  to   meet  danger,  knowing  rie.",  forecasthig    by 

by  return  of  light." 


imagmation]  that  it  will  be  redoubled  by  re.urn  or  iiant" 
And  again,  speaking  of  the  wolf  where  rendered  timid  by 

mni      L''^'^^'''•^?  '^y^  ^^^^  '^  "becomes  subject  to 
Illusions  and  to  fa  se  judgments,  which  are  the  fruit  of  the 

n^.'n£"V'"^r^'n^^^'  J"^S"^^°^«  b^«««^e  extended 
to  a  sufficient  number  of  objects,  he  becomes  the  sport  of  an 

Illusory  system,  which  may  lead  him  into  infinite  mistakes 

t  in  f  •'\'*^^  '°T^??*  ^'^^  ^^^  P""^ipl««  ^hich  have 
taken  root  in  his  mind.    He  wiU  see  snares  where  there  are 

nrT.'nf'l-'"'^^-"^^'^"'  ^''^^'^'^  ^y  ^^^^'  WiU  invert  the 
order  of  his  various  sensations,  and  thus  produce  deceptive 

danger/' &c.^  ""'"    '"''^'    '"  ^^''''''   ""''^^^ 

of  Tm^m^iL-''^^  IT  ^""^  ''*!'''  ^^'*  *^  P™ve  t^e  existence 
of  Imagination  of  the  second  order  in  animals,  but  I  think 
It  IS  a  good  one,  because  showing  that  this  faculty  exists  in 
this  degree  m  an  animal  not  having  a  very  high  grade  of 
ntel  igence-I  mean  the  wild  rabbit.  Every  oSe  who  has 
ferreted  wild  rabbits  must  have  noticed  that  if  the  warren  has 
been  ferreted  before,  the  rabbits  are  very  unwilling  to  ' bolt " 

rathrtLn  f?r7  !?  ^'  ''"°"^?^  ^"^"^^^  ^^  ^^e  ferrets 
rather  than  face  the  dangers  awaiting  them  outside.     This 

shows  that  the  rabbits  associate  (owing  to  past  experience? 

the  presence  of  a  ferret  in  their  burrows  wL  the  prience 

of  a  sportsman  outside  them  (for  it  does  not  signify  how 

careful  the  sportsman  may  be  to  keep  silent),  and  so  vivid  il 

the  loss  of  h,s  chickens    His  hounds  had  succeeded  in  captuS  seveSf  thi 

1  he  wolf  soon  approached  the  ocean  with  the  other  detachment  of  hounds^n 

woul/foZwfl.^*^"*  t'T^'^  *^^*  ^  '^'  waves  recededTrom  the  Zre  he 
iTthe  sand  thaw  ^'  °f^  as  possible,  and  in  no  instance  made  forprints 
h^i!/T  *  ^""^  r*  'l"'"''^-^  obliterated  by  the  sweU.  When  fiSlv 
he^ha^d^^gone  far  enough,  a.  he  supposed,  to  destroy  the  Bcent,  he  tried' 


INM 


if      :i 
1:1     -I 


148 


r 


.     <i 


'Hii' 


?f, 


MENTAL  EVOLUTION  IN  ANIMALS. 


the  mental  picture  of  this  outside  enemy,  that  the  animal 
will  for  a  long  time  suffer  the  immediate  pain  and  terror  at 
the  teeth  and  claws  of  the  ferret  before  venturing  to  expose 
Itself  to  the  more  remote  but  still  more  deadly  pain  which  it 
fears  at  the  hands  of  the  man. 

Coming  now  to  Imagination  of  the  third  degree,  or  that 
which  implies  the  power  of  forming  ideas  independently  of 
any  obvious  suggestions  from  without,  we   have  first  to  con- 
sider how  this  kind  of  imagination,  even  if  present  in  animals, 
could  be  expressed.     Now,  apart  from  articulate  expression 
01-  intelligent  gesture,  it  is  evident  that  the  objective  indices 
of  imagination  in  this  degree  are  so  limited  in  number  as  to 
be  well-nigh  absent.     Even,  therefore,  if  we  assume  such 
imagination  as  present  in  any  given  animal,  we  might  find  it 
difficult  to  suggest  the  kind  of  action  to  which  it  might  give 
rise,  and  which  might  be  taken  as  unequivocal  proof  of  such 
faculty.     What  we  require,  it  will  be  observed,  is  some  class 
or  classes  of  actions  which  mrct  be  due  to  imagination  of 
this  degree  and  can  be  due  to  nothing  else.     I  only  know  of 
three  such  classes,  which,  however,  are  conclusive  as  establi'^,h- 
ing  the  fact  of  such  imagination  being  present  in  the  animals 
which  display  them.     It  is  almost   needless  to  add  that 
imagination,  even  of  this   level  of   development,  may  well 
be  present  among  animals  lower  in  the  scale,  which  yet  is  not 
apparent  on  account  of  being  developed  in  lines  which  do 
not  express   themselves  in   either  of  the  three  classes  of 
actions  on  which  I  rely  in  the  case  of  the  higher  animal'-. 

The  first  of  these  actions  is  Dreaming.  This,  wherever  it 
is  found  to  occur,  constitutes  certain  proof  of  imagination 
belonging  to  what  I  have  called  the  third  degree. 

The  fact  that  Dogs  dream  is  proverbial,  and  was  long  ago 
remarked  by  Seneca  and  Lucretius.  According  to  Dr.  Lauder 
Lindsay  the  Horse  also  dreams,  as  shown  by  its  "  shuddering, 
shivering,  quivering,  quaking,  or  trembling.  These  plie- 
nomena  are  concomitants  or  results  in  the  waking  state  of 
excitement,  fear,  ardour,  impetuosity,  or  impatience.  Hence 
it  is  quite  legitimately  inferred  by  Montaigne  and  others  that 
the  same  feelings  or  mental  conditions  are  developed  during 
sleep  and  dreaming,  and  are  likely  to  be  associated  in  the 
racehorse  with  imaginary  races,  as  in  the  sporting  dog  with 
imaginary  coursing."* 

•  Mind  in  the  Lower  Animals,  voL  ii,  pp.  95-6. 


IMAGINATION. 


149 


Ignored  it.  and  in  the  dlamm  S^pp  1  ",  «'"^^°^«»t'  I  I^ave 
with  Birds    ^a  <!,«   1    "^^p^"^.  Placed  dr(3aminL'  on  a  levpl 

adequat^tidlU'  o'Si^^^^^^^^  i  ^^^  ^^-  i« 

to  the  writer  last  named  who  ,-,„         ?,  ^^^^^^^-     According 

iJirds  the  stork,  the  c'lrv  ;L^'^^^^^ 
among  the  Marimdia  the  ^^^^^^^^^  ?T^^  ^"^ 

are  incited  in  their  dream« »  p1  '  .  ^'•''^'  ^"^  ^^'^  ^^o^'. 
birds  moved  their  lei  J^thpir?"'^  "^''^^^  "'^^  ^^^^er- 
swimming;  and  Hennnhp\      ?.f^^?'  ^'  ^^  ^^  the  act  of 

Bechstein^  i-  de?cXtdtm1n^i '^^^^  Z''  f  ^^^"^  -^• 
dreams  appeared  to  be  ofthToh.\  ^"^^^"^h,  and  the 
"the  terror  begotten  durL.  sLn  ?f '^''  f  nightmares,  for 
it8  mistress's  interference  °to'Zr'.  f  ?  ^^^  ^*^  ^^^^^^^d 

I™ag.„a.„n  o,  the  thW  degree  inttJa  S'L^  of  b1i„°! 

pliantasms.    .  of  im»m-,,r'  ""•  "^  P>">ntoms  or 

And,  moveov;r.  "it  \ll7?pZ^?f  T'' ;?""*  "  *mgs. 
spectral  imaged  that  occur  ff!,,,.  ''■  *'i''  ™"«^  ''i"''  »f 
canine  rallies  for  in,,on„?  "  i"""  •""""''  «»  in  man  in 
this  subjecSl^in'fSs"'  ^uT"  ''>'tT';obia.»t     On 

thing  o  the  .ioor::"nd^^x:!:j»^Xs;r:^-^^^^^ 

P-  74.  ./  'O.nimais,  p.  60  j  and  Descent  of  Man 

et  *«?.).  Thus  Guor  asferts  ^hat^Z  «!!'''"  ^fl-  ^"'•^^^^'  ^''^  «C  97 
Bearch  of  imaginary  stranger^S  fbe^  anT^T-K^'"''  wafch-dog  pr^vi  sin 
.ones  of  panto,^^^^^^^^  towards  th//,  .,,j, 


L,i!i 


-it 


150 


MENTAL  EVOLUTION  IN  ANIMALS. 


l\v\ 


I  ('(If 


"ii  II 


I  :'   r 


■|!f 


at  the  vacant  air,  as  if  pursuing  something  against  which  it 
had  an  enmity."      And,  indeed,  this  peculiarity  of  being 
liable  to  optical  delusions  is  so  usual  and  well  marked  a 
feature  in  rabid  dogs,  that  it  generally  constitutes  the  earliest 
and  most  certain  symptom  of  disease.*  My  friend  Mr.  Walter 
Pollock  sends  me  the  following  account  of  a  Scotch  terrier 
bitch  which  he  possessed :— "  She  had  a  curious  hatred  or 
horror  of  any  thing  abnormal— for  instance,  it  was  long  before 
she  could  tolerate  the  striking  of  a  spring  bell,  which  when 
I  first  knew  her  was  a  new  experience  to  her.     She  expressed 
her  dislike  and  seeming  fear  by  a  series  of  growls  and  barks 
accompanied  by  setting  her  hair  up  on  end.      She  used  from' 
tmie  to  time  to  go  through  exactly  the  same  performance 
after  gazing  fixedly  into  what  seemed  to  be  vacancy.     This 
attracted  my  attention,  and  I  used  to  be  on  the  look  out  for 
it,  but  carefully  avoided  in  any  way  tempting  her  to  make 
any  display  of  this  peculiarity.     I  simply  watched  her  when- 
ever I  was  alone  with  her.     The  constant  repetition  in  these 
circumstances  of  her  seeming  to  see  some  enemy  or  portent 
unseen  by  me,  and  giving  vent  to  her  feelings  in  the  way 
already  described,  led  me  to  the  conclusion  that  at  these 
tunes  she  was  the  victim  of  optical  illusion  of  some  kind.     I 
could,  as  I  have  already  hinted,  produce  the  same  effect  upon 
her  by  doing  some  unexpected  and  irrational  thing,  until  she 
had  become  accustomed  to  this  kind  of  experiment      But 
after  this  the  seeing,  as  it  seemed  to  be,  of  some  sort  of 
phantom  remained  unabated.      I  had  no  opportunity  of  dis- 
cerning whether  the  phenomena  occurred  at  any  regular 
intervals,  or  whether  they  were  more  frequent  after  sleep 
than  at  other  times." 

Pierquin  describes  a  female  ape  which  had  a  sun-stroke, 
and  afterwards  use  to  become  terror-struck  by  delusions  of 
some  kind.  She  also  used  to  snap  at  imaginary  objects,  and 
"  acted  as  if  she  had  been  watching  and  catching  at  insects 
on  the  wing."t 

It  seems  needless  for  our  present  purpose  to  give  more 
evidence  on  the  fact  of  animals  being  subject  to  delusions, 
and  so  I  sliall  pass  on  to  the  third  class  of  facts  on  which  I 
rely  as  evidence  that  animals  present  Imagination  of  what  I 
have  called  the  third  order.      This  class  of  facts  consists  o\ 

*  See  Youat,  On  the  Bog,  under  Rabies, 

t  Traite  de  la  Folie  des  Animaux,  ^c,  tome  i,  p.  93. 


IMAGINATION,  jgj 

fpint  with  which  jaded  hor^s  return  nn  ^^    '   t^  ^''^*"' 

repose.      AgS  The  Tsire  wlnT""'"'"""''!''  "'  '<""•  "'"i 

picture,  or  imagination  of  E  S  them  to  retain  a  mental 
Tlie  primptS  of  h?;  L!^  Previously  happy  experience, 
as  to  indTthe  anima  s  to  W '\T  T  ^^^^""^tly  so  strong 
hundreds  of  mTles T?  avel  fo/n  ^ ''  ^"°'''  ""^  ^^^^g"««  «f 
to  the  scenerw^iich  occur, v  /hi      •  °^'  ?"'^'''  "^  '^^"^"^"g 

dogs.   cats.  anrToLrXn     ^m^r^^^^^ 

homes,  give  repeated  IS  ^ai^  ^^}^^J^^  "oni  their  former 

crushes  and  oveChelms  Jhe  fao^„ir'''"/'l  '^  ^^'  ^''^-  ^^ 
trates  the  energies  of    he  bo^^T^^^^^  -'  ^^^  ^""" 

encaged,  become  so  utterly  spTrLbro^en  2?V''^%  ^^^^ 
nourishment,  pine  for  a  f e wTys  and  dV  T v  ^- ''^"''.  ^" 
larly  the  case  Mith  song-S'  ^'"'  J^Z'T"']'''- 
Monkey  is  caught  wlipn  f„ii  -1  /    "^^  *"®  Howling 

reuses;;!,  fo^d^^dlTtaa'ff;":^^^^^^^^ 

with  the  Puma-  nnrt  K,„»i„  !,».,'  "'«  "so  the  same 

ensues  so  Lmed'iatdv  S"*.?/"""',  "">'.  death  sometimes 

and  violent  p"  stJeti  Ihe  .ni„d".°"'^  '™^  """^  »  »■"'<'» 

Pini^u^nt  confinTm'e^ttrttla't'"^  '"'^-P^'^'-n  of 
■nere  absence  of  liberty  or  ^ht„^  fe^  inay  be  due  to  the 
any  mental  and  coSsted  n2r.  nr"^"  •"  "'  ^''"^  ""><"" 
think  that  this  ob/ection^s  pSded  in"'^;r'  'T"?"'  ^ 
cases  to  which  I  shall  next  refer  and  wh.Vh      '""^-  "'i'^''^'"'' 

except  the  sudden  withLwfi"?  *''"  <'™ditions  of  life, 
whiei  the  Inima"  "  stS/'aLchT  °I  T'^"""  f 
i^nown  a  case  in  which  a  ^r^J^^  ^^^d,  7t 

Thompson,  Passions  of  Animals,  pp.  64-5. 


-A 

i 

f! 

1 

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i 

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■:":r!::arrLrar.:ar:;-rj 


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152 


MENTAL  EVOLUTION  IN  ANIMALS. 


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sudden  removal  of  his  mistress,  refused  all  food  for  a  number 
of  days,  so  that  it  was  thought  he  must  certainly  die,  and  his 
life  was  only  saved  by  forcing  him  to  eat  raw  eggs.  Yet  all 
his  surroundings  remained  unchanged,  and  every  one  was  as 
kind  to  him  as  they  always  had  been.  And  that  the  cause 
of  his  pining  was  wholly  due  to  the  absence  of  his  beloved 
mistress,  was  proved  by  the  fact  that  he  remained  perma- 
nently outside  her  bedroom  door  (although  he  knew  she  was 
not  inside),  and  could  only  be  induced  to  go  to  sleep  by 
giving  him  a  dress  of  hers  to  lie  upon.  No  one  could  have 
seen  this  dog  without  being  persuaded  that  he  had  a  constant 
mental  picture  of  his  mistress  in  his  imagination,  and  suffered 
the  keenest  mental  anguish  from  her  continued  absence. 
Similarly  there  are  numberless  anecdotes  on  record,  most  of 
which  are  probably  true,  of  dogs  actually  dying  under  such 
circumstances. 

All  these  facts,  then,  taken  together — ^viz.,  dreaming,  de- 
lusions, "home  sickness,"  and  pining  for  friends— clearly 
prove  the  presence  among  higher  animals  of  Imagination  in 
v/hat  I  have  called  the  third  order.  A  question  may  here 
arise  as  to  whether  I  have  not  in  the  diagram  placed  the  rise 
of  Imagination  too  low.  I  place  the  first  origin  of  this 
faculty  on  level  19,  which  corresponds  with  that  of  the 
MoUusca  and  an  infant  seven  weeks  old.  This  question,  like 
all  others  of  line-drawing  among  the  psychological  faculties, 
is  confessedly  a  difficult  one ;  but  the  reasons  why  I  have 
placed  the  dawn  of  Imagination  so  low  in  the  psychological 
scale  are  as  follows  : — 

It  will  be  remembered  that  the  kind  of  Imagination 
which  we  have  recently  been  coi^.sidering  belongs  to  what  I 
consider  a  high  level  of  development.  That  is  to  say,  I  con- 
sider the  power  of  dreaming  to  occupy  a  place  about  one 
third  of  the  distance  between  the  first  dawn  of  the  imagina- 
tive faculty  and  its  maximum  development  in  a  Shakespeare 
or  a  Faraday.  I  so  consider  it  because  I  believe  that  to  pass 
through  what  I  have  called  the  first  three  stages,  so  as  to 
arrive  at  the  power  of  forming  mental  pictures  independently 
of  sensuous  suggestions  from  without,  the  imaginative  faculty 
has  made  so  enormous  a  progress  from  its  earliest  begin- 
nings, that  the  rest  of  its  development  along  the  same 
lines  is  really  nothing  more  than  a  function  of  the  faculty 
of  Abstraction.      Superimpose  upon   the  psychology  of   a 


IMAGINATION. 


153 


terrier  which  pmes  for  its  absent  mistress  an  elaborate 
structure  of  abstract  ideation,  and  the  terrier's  imaginative 
faculty  would  begin  to  rival  that  of  man.  Of  course  it  will 
j^  u.  *ha^  abstraction  presupposes  imagination,  and  so 
undoubtedly  it  does ;  still  the  two  are  not  identical,  as  is 
proved  by  the  fact  that  for  the  building  up  of  abstraction  to 
any  exalted  height,  language,  or  mental  symbolism  of  some 
kind,  IS  indispensable ;  and  mental  symbols  are  so  many 
artitices  for  the  saving  of  imagination. 

Now  if  at  first  sight  it  seems  absurd  to  accredit  a  mollusk 
with  imagination,  we  must  remember  exactly  what  we  mean 
by  imagination  in  the  lowest  possible  phase  of  its  develop- 
ment.   We  mean  merely  the  power  ol  forming  a  definite 
mental  picture,  or  of  retaining  a  mt  iory,  no  matter  of  how 
rudimentary  a  kind  ;  provided  that  the  memory  implies  some 
dim  idea  of  an  absent  object  or  experience,  and  not,  as  in  the 
case  of  an  infant  disliking  the  taste  of  strange  milk,  merely 
an  immediate  perception  of  contrast  between  an  habitual  and 
a  present  sensation.      And  that  we  find  such  a  level  of 
mental  development  as  low  down  in  the  zoological  scale  as 
the  Crasteropoda,  would  seem  to  be  proved  by  the  fact  already 
alluded  to  of  hmpets  returning  to  their  homes  in  the  rocks 
after  feeding.     Of  course  the  mental  image  which  a  limpet 
forms  of  Its  home  m  a  rock  cannot  be  supposed  to  be  com- 
parable m  point  of  vividness  or  complexity  with  the  mental 
image  that  a  horse  retains  of  its  stall,  or  a  dog  of  its  kennel  • 
still,  such  as  It  is,  It  is  a  mental  image,  and  therefore  betokens 
imagination.     More  vivid,  and  therefore  more  definite,  is  the 
mental  image  that  a  spider  forms  of  her  lair,  who  when  dis- 
lodged  and  carried  away  to  a  short  distance  again  returns  to 
her  old  home.     (Level  20.)      With  a  still  further  advance  in 
the  power  of  mental  imagery  (level  21)  we  find  supplied  the 
psychological  conditions  for  the  ideation  of  cold-blooded  Ver- 
tebrata,  such  as   the  determination  displayed  by  mif^ratory 
Inshes  (notably  the  salmon)  to  visit  particular  localities  in 
tlie  spawning  season.      On  the  next  level  (22)  we  reach  the 
higher  Crustacea,  which,  as  we  have  already  seen,  are  able  to 
imagine  m  a  high  degree.      Next  we  come  to  Eeptiles.  con- 
cerning which  I  may  quote   the  following  anecdote  from 
Lord  Monboddo:   "I  am  well  informed  of  a  tame  serpent  in 
the  East  Indies,  which  belonged  to  the  late  Dr.  Vigot  once 
kept  by  him  in  the  suburbs  of  Madras.     This  serpent  was 


I]'  I 


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1 

MENTAL  EVOLUTION  IN  ANIMALS. 

taken  by  the  French,  when  they  invested  Madras,  in  the  late 
war,  and  was  carried  to  Pondicherry  in  a  close  carriage.  But 
from  thence  he  found  his  way  back  again  to  his  old  quarters, 
though  Madras  is  over  one  hundred  miles  distant  from 
Pondicherry."  If  we  substitute  yards  for  miles,  similar  cases 
are  on  record  with  regard  to  frogs  and  toads — which  from  being 
so  numerous  can  scarcely  all  be  false.  And  that  some  reptiles 
have  an  imagination  passing  into  what  I  have  called  the  third 
stage  is  proved  by  the  case  of  the  python  mentioned  in  "Animal 
Intelligence,"  which,  when  sent  to  the  Zoological  Gardens, 
pined  for  its  previous  master  and  mistress.  The  Cephalopoda 
and  Hymenoptera  have  already  been  alluded  to.  Lastly,  on 
the  next  level  (25)  we  attain  in  Birds  to  imagination  proved 
to  be  unquestionably  of  the  third  degree  by  the  phenomenon 
of  dreaming.  Above  this  level  it  is  not  of  so  much  interest  to 
trace  the  improvement  of  the  faculty.  Such  improvement 
throughout  the  subsequent  levels  tUl  man,  probably  consists 
only  in  a  progressive  advance  through  imagination  of  the 
third  degree — it  being  I  think  highly  improbable,  and  cer- 
tainly not  betokened  by  any  evidence,  that  imagination  in 
any  animal  attains  to  what  I  have  called  the  fourth  degree, 
which  I  therefore  consider  distinctive  of  man. 

*'  For  know  that  in  the  soul 
Are  many  lesser  faculties  that  servo 
Reason  as  chief.    Among  these.  Fancy  next 
Her  office  holds.    Of  all  external  things, 
Which  the  five  watchful  senses  represent. 
He  forms  imaginations,  airy  shapes  ; 
Which  Reason  joining  or  disjoining,  forms 
All  that  we  affirm,  or  what  deny, 
And  call  our  knowledge." — Miltoit. 

Before  taking  leave  of  Imagination  there  are  two  branches 
of  the  subject  which  I  should  like  briefly  to  consider.  One 
is  the  opinion  held  by  Comte  that  the  higher  animals  present 
ideas  of  Fetishism.  On  this  topic  I  cannot  more  briefly 
convey  the  material  which  I  have  to  render  than  by  quoting 
a  previous  publication  of  my  own  from  "  Nature."*  "  Mr. 
Herbert  Spencer  in  his  recently  published  work  on  the  '  Prin- 
ciples of  Sociology '  treats  of  the  above  subject.  He  says, 
*  I  believe  M.  Comte  expressed  the  opinion  that  fetichistic 
conceptions  are  formed  by  the  higher  animals.    Holding,  as  I 

•  Vol.  xvii,  p.  168,  et  seq. 


IMAGINATION. 


165 


have  given  reasons  for  doing,  that  fetichism  is  not  original 
but  derived.  I  cannot,  of  course,  coincide  in  this  ^ew 
Nevertheless  I  think  the  behaviour  of  intelligent  LS 
elucidates  he  genesis  of  it.  I  have  myself  witnessed  in 
dogs  two  illustrative  cases.'       One  of  thirconsistld  Tn  ^ 

a'o?e  eidtf  f  ^^^p^fr^  fth  r^irSe'ntdi; 

tnrust  one  end  of  it  against  his  palate,  when  'giving  a  vein 
he  dropped  the  stick,  rushed  to  a  distance  from^t  ^and 
betrayed  a  consternation  which  was  particularly  W^^^^^^^^ 
m  so  ferocious-lookmg  a  creature.     Only  after  cautiou?flT 

the  stick  wh^^^H-^^^^^^^  ^^^^\^  ^'^y  '^'^^^y  the  fa  Jt  that 
tne  stick,  while  displaying  none  but  the  properties  he  was 

SiTth'/f 'T  ^t^T^ded  by  him  as  anVt^^e  ageT 
but  that  when  it  suddenly  inflicted  a  pain  in  a  way  nevei' 
before  experienced  from  an  inanimate  object,  he  was  led  Z 
a  moment  to  class  it  with  animate  objects,  and  tTreiard  it 
as  capable  of  again  doing  him  injury.    'similarly,in  thfi^nd 
of  the  primitive  man,  knowing  scarcely  more  of  natural 
causation  than  a  dog,  the  anomSlous  behLour  of  an  S 
previously  classed  as  inanimate  suggests  animation       The 
dea  of  voluntary  action  is  made  nascent;   and  there  arises  a 
tendency  to  regard  the   object  with  al'arm,  lestTt  should 
act  in  some  other  unexpected  and  perhaps  m'ischievous  way 
The  vague  notion  of  animation  thus  aroused  will  obviouslv 

thTr  %T'  ^1"^'"  r'^°"'  ^  f^^t  ^«  the  developr^nt  of 
the  ghost-theory  furnishes  a  special  agency  to  whkh  the 
anomalous  behaviour  can  be  ascribed.'     °      "^        ^'^''"^  ^He 
•  .  "?"h^, other  case  observed  by  Mr.  Spencer  was  that  of  an 
intelligent  retriever.      Being  by  her  duties  as  a  retriever  leS 
to  associate  the  fetching  of  game  with  the  pleasure  of  the 
person  to  whom  she  brought  it,  this  had  become  in  her  mind 
an  act  of  propitiation;   and  so,  'after  wagging  her  tail "nd 
grinmng,  she  would  perform  this  act  of  propitiatil  as  neail  v 
as  practicable  in  the  absence  of  a  dead  bV    Sing  abou 
she  would  pick  up  a  dead  leaf  or  other  small  object   and 
would  bring  It  with  renewed  manifestations  of  fSSiness 
Some  kindred  state  of  mind  it  is  which,  I  believe,  prompts 
tiie^sava,ge  to  certain  fetichistic  observances  of  an  anSous 

"  These  observations  remind  me  of  several  experiments  I 
made  some  years  ago  on  this  subject,  and  which  Le  periiapa 


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156 


MENTAL  EVOLUTION  IN  ANIMALS. 


( , 


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worth  publishing.  I  was  led  to  make  the  experiments  by 
reading  the  instance  given  by  Mr.  Darwin  in  the  '  Descent  of 
Man'  of  the  large  dog  which  he  observed  to  bark  at  a  parasol 
as  it  was  moved  along  a  lawn  by  the  wind,  so  presenting  the 
appearance  of  animation.  The  dog  on  which  I  experimented 
was  a  Skye  terrier — a  remarkably  intelligent  animal,  whose 
psychological  faculties  have  already  formed  the  subject  of 
several  communications  to  this  and  other  periodicals.  As  all 
my  experiments  yielded  the  same  results,  I  will  only  mention 
one.  The  terrier  in  question,  like  many  other  dogs,  used  to 
play  with  dry  bones,  by  tossing  them  in  the  air,  throwing 
them  to  a  distance,  and  generally  giving  them  the  appearance 
of  animation  in  order  to  give  himself  the  ideal  pleasure  of 
worrying  them.  On  one  occasion,  therefore,  I  tied  a  long  and 
fine  thread  to  a  dry  bone,  and  gave  him  the  latter  to  play 
with.  After  he  had  tossed  it  about  for  a  short  time,  I  took 
the  opportunity,  when  it  had  fallen  at  a  distance  from  him 
and  while  he  was  following  it  up,  of  gently  drawing  it  away 
from  him  by  means  of  the  long  invisible  thread.  Instantly 
his  whole  demeanour  changed.  The  bone  which  he  had  pre- 
viously pretended  to  be  alive  now  began  to  look  as  if  it 
were  really  alive,  and  his  astonishment  knew  no  br  ads.  He 
first  approached  it  with  nervous  caution,  as  Mr.  Spencer 
describes;  but  as  the  slow  receding  motion  continued,  and 
he  became  quite  certain  that  the  movement  could  not  be 
accountec.  for  by  any  residuum  of  the  force  which  he  had 
himself  communicated,  his  astonishment  developed  into  dread, 
and  he  ran  to  conceal  himself  under  some  articles  of  fur- 
niture, there  to  behold  at  a  distance  the  'uncanny'  spectacle 
of  a  dry  bone  coming  to  life. 

"  Now  in  this  and  all  my  other  experiments  I  have  no 
doubt  that  the  behaviour  of  the  terrier  arose  from  his  sense  of 
the  mysterious,  for  he  was  of  a  highly  pugnacious  disposition, 
and  never  hesitated  to  fight  any  animal  of  any  size  or  fero- 
city ;  but  apparent  symptoms  of  spontaneity  in  an  inanimate 
object  which  he  knew  so  well,  gave  rise  to  feelings  of  awe 
and  horror,  which  quite  enervated  him.  And  that  there  was 
nothing  fetichistic  in  these  feelings  may  safely  be  concluded 
if  we  reflect,  with  Mr.  Spencer,  that  the  dog's  knowledge  9f 
causation  for  all  immediate  purposes  being  quite  as  correct 
and  no  less  stereotyped  than  is  that  of  'primitive  man,' 
when  an  object  of  a  class  which  he  knew  from  uniform  past 
experience  to  be  inanimate  suddenly  began  to  move,  he  must 


i- 


IMAGINATION. 


157 


have  felt  the  same  oppressive  and  alarming  sense  of  the 
mysterious  which  uncultured  persons  feel  under  similar  cir- 
cumstances.    But  further,  in  the  case  of  this  terrier,  we  are 
not  left  with  d,  priori  inferences  alone  to  settle  this  point  for 
another  experiment  proved  that  the  sense  of  the  mysterious 
in  this  animal  was  sufficiently  strong  in  itself  to  account  for 
hehayiour.     Taking  him  into  a  carpeted  room,  I  blew  a 
soap-bubble,  and  by  means  of  a  fitful  draught  made  it  inter- 
mittently glide  along  the  floor.     He  became  at  once  intensely 
interested,  but  seemed  unable  to  decide  whether  or  not  the 
fitful  object  was  alive.     At  first  he  was  very  cautious,  and 
foUowed  It  only  at  a  distance;  but  as  I  encouraged  him  to 
examine  the  bubble  more  closely,  he  approached  it  with  ears 
erect  and  tail  down,  evidently  with  much  misgivin^^,  and  the 
moment  it  happened  to  move  he  again  retreated."'  After  a 
time,  however,  during  which  I  always  kept  at  least  one  bubble 
on  the  carpet,  he  began  to  gain  more  courage,  and  the  scientific 
spirit  overcoming  his  sense  of  the  mysterious,  he  eventually 
became  bold  enough  slowly  to  approach  one  of  the  bubbles 
and  nervously  to  touch  it  with  his  paw.     The  bubble    of 
course,  immediately  burst,  and  I  certainly  never  saw  astonish- 
ment more  strongly  depicted.      On  then   blowing  another 
bubble,  I  could  not  persuade  him  to  approach  it  for  a  crood 
while;  but  at  last  he  came,  and  carefully  extended  his  paw 
as  before,  with  the  same  result.     But  after  this  second  trial 
nothing  would  induce  him  again  to  approach  a  bubble  and 
on  pressing  him  he  ran  out  of  the  room,  which  no  coaxinrr 
would  persuade  him  to  re-enter.  ® 

"One  other  example  will  suffice  to  show  how  strongly 
developed  was  the  sense  of  the  mysterious  in  this  aninml 
When  alone  with  him  in  a  room  I  once  purposely  tried  the 
effect  on  him  of  making  a  series  of  hideous  grimaces.  At 
first  he  thought  I  was  only  making  fun ;  but  as  I  persistently 
disregarded  his  caresses  and  whining  while  I  continued  unna- 
turally to  disturb  my  features,  he  became  alarmed;  slunk 
away  under  some  furniture,  shivering  like  a  frightened  child. 
He  remained  in  this  condition  till  some  other  member  of  the 
family  happened  to  enter  the  room,  when  he  emerged  from 
his  hiding  place  in  great  joy  at  seeing  me  again  in  my  ritrht 
mmd.  In  this  experiment,  of  course,  I  refrained  from  makmcr 
any  sounds  or  gesticulations,  that  might  lead  him  to  think  I 
was  angry.  His  actions  therefore  can  only  be  explained  by 
his  horrified  surprise  at  any  apparently  irrational  behaviour, 


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158 


MENTAL  EVOLUTION  IN  ANIMALS. 


.*  ' 


ii 


t.e.,  by  the  violation  of  his  ideas  of  uniformity  in  matters 
psychological.    It  must  be  added,  however,  that  I  have  tried 
the  same  experiment  on  less  inteUigent  and  lees  sensitive 
terriers  with  no  other  eflTect  than  causing  them  to  bark  at  me. 
i.  wiU  only  add  that  I  believe  the  sense  of  the  mysterious  to 
be   the  cause  of  the  dread  which   many  animals  show  of 
thunder.    I  am  led  to  think  this,  because  I  once  had  a  setter 
winch  never  heard  thunder  tiU  he  was  eighteen  months  old 
and  on  then  hearing  it  I  thought  he  was  about  to  die  of 
inght,  as  I  have  seen  other  animals  do  under  various  circum- 
stances. And  so  strong  was  the  impression  which  his  extreme 
terror  left  behind,  that  whenever  afterwards  he  heard  the 
boom  of  distant  artiUery  practice,  mistaking  it  for  thunder 
he  became  a  pitiable  object  to  look  at,  and,  if  out  shootin-' 
would  endeavour  to  bury  himself  or  bolt  home.    After  having 
heard  real  thunder  on  two  or  three  subsequent  occasions  hi? 
dread  ot  the  distart  cannon  became  greater  than  ever:  so 
that  eyentuaUy,  though  he  keenly  enjoyed  sport,  nothing 
would  induce  him  to  leave  his  kennel,  lest  che  practice  might 
begin  wlien  he  was  at  a  distance  from  home.     But  the  keeper 
who  had  a  large  experience  in  the  training  of  dogs,  assured 
me  it  I  allowed  this  one  to  be  taken  to  the  battery  in  order 
that  he  might  learn  the  true  cause  of  the  thunder-like  noise 
he  would  again  become  serviceable  in  the  field.     The  animal' 
however,  died  before  the  experiment  was  made."* 

Thus  I  think  we  may  safely  set  down  the  sense  of  the 
mysterious  as  thus  undoubtedly  displayed  by  intelligent  doers 
—and  also,  I  may  add,  by  many  horses  when  going  aloncr^a 
dark  road,  hearing  strange  sounds,  or  seeing  unaccustomed 
^•u-1  •  ~"  .  ®^^*^  ^^  imagination  in  suggesting  vague  pos- 
sibilities m  circumstances  perceived  to  be  unusual;  just  as 
with  children  under  similar  circumstances  the  undefined 
imagination  of  possible  harm  springing  out  of  such  circum- 
stances in  some  unthought-of  manner,  engenders  that  feelincr 
of  unreasonable  dread  which  we  may  in  both  cases  call  I 
sense  ot  the  mysterious. 

on  1™  '""^  T""^^  have  been  the  case,  however,  I  have  little  doubt,  for 
^LZ  T  T  ^^^"^  ^  ''"J^''""  °^  ^PP^"^  ^*^r«  being  shot,  out  of  baf^s  i  pon 
th9  wooden  floor  of  an  apple-room,  the  sound  in  the  house  as  each  bLTaa 
shot  closely  ivsembled  that  of  distant  thunder.  The  setter,  therefore  hSume 
terribly  alarmed;  but  when  I  took  him  to  the  apple-room  and  sho;S  S 

to  the  house  he  listened  to  the  riuubling  with  all  cheerfulness  ^''^^"» 


DTSTINCT. 


159 


CHAPTER  XL 

Instinct. 

Definition. 

I  SHALL  begin  this  important  and  extensive  part  of  mv 
subject  by  repeating  the  definition  of  Instinct  which  I  iSd 
down  m  my  former  work.  It  will  be  remembered  that  for 
folW--  ^'''''^'^  ^  '^'''  ^"^'"'^  '^'  '^"^  Instinct  as 
"Instinct  is  reflex  action  into  which  there  is  imported 
the  element  of  consciousness.  The  term  is  therefore  a 
generic  one,  comprising  all  those  faculties  of  mind  which  are 

dS^nl  '^  '^'^''^^^^  "\^  "^^P^i^^  ^'^^^^^^  antecedent  to  Z 
dividual  experience,  without  necessary  knowledge  of  the 
relation  between  means  employed  and  ends  attained  but 
similarly  performed  under  similar  and  frequently  recuiW 
circumstances  by  aU  the  individuals  of  the  same  specfes  "  ^ 
Keterring  the  reader  to  the  context  for  my  iustification  of 
this  definition  M  shall  here  only  further  ZLIT^J^ 
statement.  It  follows  from  the  above  definition  of  iSnct 
that  a  stimulus  which  evokes  a  reflex  action  is,  at  mSa 
sensation  ;t    but  r.  stimulus   which  evokes   an  instS've 

a^nte^M^^'^'P'""-  .t'^'l^''^'  I  ^^-^  alreadylaTd  L 
and^a  Lr?  '^'''"'"^  *^'  distinction  between  a  sensation 
and  a  perception,  my  meaning  now  will  be  clearly  under- 
stood. For  If  a  perception  differs  from  a  sensation  in  that  it 
presents  a  mental  element,  and  if  an  instinctive  action  differs 

IZVt^"''  '.tT  ^^  '^^\  ''  P^^^^^^«  ^  ^^^t^l  element 
tS.tr  ^\'\'  ''r'^^  '"PP^^^^  by  a  sensation  is  to 
a  reflex  action  what  a  stimulus  supplied  by  a  perception  is  to 
an  instinctive  action;  because  if  a  sensation^ could  act  as  a 

*  Animal  Intelligence,  pp.  10-17. 

in  X  I  -^^  "'^*'  ™°'*''"  ^^<^'i"se  such  a  stimulus  may  be  less  tlian  a  sensaHon 
m  that  It  may  never  cross  the  field  of  consciousness:  sensation, 


nil    If     ii 


Mi.liJi: 


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160 


5fc  ! 


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11*     Hi 
\  I  [If    <  '  •  -'i . 


I  ' 


MENTAL  EVOLUTION  IN  ANIMALS. 


Stimulus  to  an  action  apparently  instinctive,  ex  hypothed  the 
acton  could  not  be  (according  to  my  definition)  really 
instmctive ;  and  conversely,  if  a  perception  could  act  as  a 
stimulus  to  an  action  apparently  reflex,  the  action  could  nob 
be  (according  to  my  definition)  a  true  reflex.  Therefore  if 
we  agree  to  limit  the  term  Instinct  to  nervous  processes 
involving  a  mental  element,  it  follows  that  this  element  is 
perception,  and  that  it  is  always  involved  in  every  stimulus 
leading  to  instinctive  action. 

nT.lJ!.l^r w  """  ^"^  f  "1?'^^  principles  of  classification  it  is 
only  needful  for  me  further  to  quote  the  following  extract 
Iroiii  my  previous  work : —  ^ 

io  171'^-  'T^  ™Port,ant  point  to  observe  in  the  first  instance 
IS  that  icstmct  involves  mental  operations;  for  this  is  the 
only  point  that  serves  to  distinguish  instinctive  from  reflex 
action.      Eeflex  action,  as  already  explained,  is  non-mental 
neuro-muscular  adaptation  to  appropriate  stimuli;   but  in- 
stinctive action  18  this  and  something  more;  ther^  is  in  it 
the  element  of  mind.     No  doubt  it  is  often  difficult  or  even 
impossible,  to  decide  whether  or  not  a  given  action  implies 
t^Ulfr"  "^  '^'  «^ind.element-i..,  conscious  as  distin! 
guishedfrom  unconscious  adaptation;  but  this  is  altoc^ether 
a  separate  matter,  and  has  nothing  to  do  with  the  question 
ot  defining  instinct  in  a  manner  which  shall  be  formally 
exclusive,  on  the  one  hand  of  reflex  action,  and  on  the  other 
of  reason.     As  Virchow  truly  observes,  'it  is  difficult  or 
impossible  to  draw  the  hue  between  instinctive  and  reflex 
action;   but  at  least  the  difficulty  may  be  narrowed  down  to 
deciding  in  particular  cases  whether  or  not  an  action  falls 
wTvtt'dS.^lf  category  of  definition;  there  is  no  reason 
Jp  Ii,     /i   ?^^^  '^°''^'^  ^"'^  ^^  account  of  any  ambiguity 
of  the  definitions  themselves.      Therefore  I   endeavour  to 
draw  as  sharply  as  possible  the  line  whf.  h  in  theory  should 
be  .aken  to  separate  instinctive  fromrehex  action;  and  this 
line,  as  I  have  already  said,  is  constituted  by  the  boundary 
ot  non-mental  or  unconscious  adjustment,  with  adjustment  in 
wnich  there  is  concerned  consciousness  or  mind  " 

T.1..^  '^^^  r"^  P'^iT"?  *^  '^^'^'  ^y  ^  ^^^  selected  examples, 
what  has  been  called  the  Perfection  of  Instinct;  next  I 
shall  similarly  Illustrate  the  Imperfection  of  Instinct;  and 
lastly,  I  shall  discuss  the  important  question  of  the  Origin 
and  Development  of  Instinct.  wi  tuo  v^ii^ia 


PERFECTION  OP  INSTINCT. 


161 


Perfection  of  Instinct. 
An  instinct  may  be  said  to  be  perfect  when  it  is  nerfertlv 
adapted  to  meet  those  circumstances  in  the  life  of  an  aniS 
for  the  meeting  of  which  the  instinct  exists  ami  ?f  ffT 
instmct  this  perfection  must  be  exhTbi  eTls'iXendent  of 
mL?  f  1'  "^^^'^dual  experience.  We  may  therefore  best 
d    ful^^^^^^^^^^^^  ''  ^"^^\^^  ^y  eonsii"  wot 

S  aStm/nt.  wTY  ^""""^  '^f  ^"^^^y  ^^«"«^  ^«d  com. 

on  tWs  I'S  ?r  ^^^n  ^^'1^^'"?  ^^  ^^^  ^""^^«t  researches 

?als  ty  of"£;?ew  "^^^^^^^^^         f'""'^  >-^  ,^-'^ti-  the 
mnv  io  t,„;i  •  ,  ""  ""*  supposed  examples  of  instinct 

SstmSrS  E"'™  ""'f  ■°''  -^P'"  '«»™"S.  toitSn 
comes  in  o  the  1^M°  '"T'' """  "  y°™S  ''»■'•<«■  "»■""•» 

inj  of  chickens  which  he  liberated  from  tlie'e^-^and  hided" 
before  their  eyes  had  heen  able  to  perform  anVact  of  vWon 
fto,^"^''  "l"'  r  ''^'"°""S  *e  hood  aft"r  aL,  od  ™S 

beyond  their  reL.  as  babies  arsaidTrLs^Hh:  moof 
and  they  may  be  said  to  have  invariahlfhit^he  obleXat 

tro,;iTcMikrwT.e''lll'',t°':,,i,''  *"''7'««»''.  if«</»-W.  Feb™.,,,  1873 
yet  ten  jenrs  old— it  leems  diinrT.lt  .„„r'  .,"'"  'M^m  ttu  artide— not 
instinct m  the  quowim. in  The  SclesLou.  ''»-«">i"«ion«rj  vie.-  of 


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162 


MENTAL  EVOLUTION  IN  ANIMALS. 


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Hil 


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which  they  struck— they  never  missed  by  more  than  a  hair's 
breadth,  and  that,  too,  when  the  specks  at  which  they  aimed 
were  no  bigger,  and  less    ■  ii  te,  ih..n  the  smallest  dot  of  an  i 
10  seize  between  th^  ^,  .nts  uC  the  mandibles  at  the  very 
instant  of  striking  seemed  a  more  difficult  operation.    I  have 
seen  a  chicken   seize  and  swallow   an   insect  at  the  first 
attempt ;    most  frequently,  however,  they  struck  five  or  six 
times  liftmg  once  or  twice  before  they  succeeded  in  swallow- 
ing their  first  food.     The  unacquired  power  of  followinrr  by 
sight  was  very  plainly  exemplified  in  lue  case  of  a  chiJken 
that,  after  being  unhooded,  sat  complaining  and  motionless 
tor  six  minutes,  when  I  placed  my  hand  on  it  for  a  few 
seconds     On  removing  my  hand  the  chicken  immediately 
followed  It  by  sight  backward  and  forward,  and  all  round  the 
table.     To  take,  by  way  of  example,  the  observations  in  a 
single  case  a  little  in  detail :— A  chicken  that  had  been  made 
the  subject  of  experiments  on  hearing,  was  unhooded  when 
nearly  tnree  days  old.     For  six  minutes  it  sat  chirpin"  and 
looking  about  it;  at  the  end  of  that  time  it  followed  with  its 
head  and  eyes  the  movements  of  a  fly  twelve  inches  distant  • 
at  ten  minutes  it  made  a  peck  at  its  own  toes,  and  the  next 
instant  it  made  a  vigorous  dart  at  the  fly,  which  had  come 
withm  reach  of  its  neck,  and  seized  and  swallowed  it  at  the 
farst  stroke ;  for  seven  minutes  more  it  sat  calling  and  looking 
about  It,  when  a  hive-bee  coming  sufficiently  near  was  seized 
at  a  dart  and  thrown  some  distance,  much  disabled.     For 
twenty  minutes  it  sat  on  the  spot  where  its  eyes  had  been 
unveiled  without  attepipting  to  walk  a  step.     It  was  then 
placed  on  rough  ground  within  sight  and  call  of  a  hen  with  a 
brood  of  its  own  age.     After  standing  chirping  for  about  a 
minute,  it  started  off^  towards  the  hen,  displaying  as  keen  a 
perception  of  the  qualities  of  the  outer  world  as  it  was  ever 
likely  to  possess  in  after  life.     It  never  required  to  knock  its 
head  against  a  stone  to  discover  that  there  was  '  no  road  that 
way.      It  leaped  over  the  smaller  obstacles  that  lay  in  its 
path  and  ran  round  the  larger,  reaching  the  mother  in  as 
nearly  a  straight  line  as  the  nature  of  the  ground  would  per- 
mit.   This,  let  it  be  remembered,  was  the  first  time  it  had 
ever  walked  by  sight." 

Further,  "When  twelve  days  old  one  of  my  little  proteges, 
while  running  about  beside  me,  gave  the  peculiar  chirr 
whereby  they  announce  the  approach  of  danger.    I  looked 


PERFECTION  OP  INSTINCT. 


1P3 


np,  and  behold  a  sparrow-hawk  was  hoveriim  at  a  ereat 
height  over  head.  E.iually  striking  was  the  ef!ect  of  the 
hawk  8  voice  when  heard  for  the  first  time.  A  youn-  turkey 
whieh  I  had  adopted  when  chirping  within  the  uncracked 
shell  vyas  on  the  morning  of  the  tenth  day  of  its  life  eating  a 
comfortal^e  l.roaklast  from  my  hand,  when  the  youn^  hawk 
in  a  cupboard  just  beside  us,  gave  a  shrill  chip,  chrp.  chip! 
Like  an  arrow  the  poor  turkey  shot  to  the  other  side  of  the 
room,  and  stood  there  motionless  and  dumb  with  fear,  until 

fnr.^tf'f. ""  '^"'"'^  ''>^'  ^^^^"  it  ^^^rted  out  at  the  open 
door  right  to  the  extreme  end  of  the  passage,  and  theiv,  silent 
and  cv mched  in  a  corner,  remained  for  ten  minutes.  Several 
times  during  the  course  of  that  day  it  again  heard  these 
trSoTS:-'"'  "  every  instance  with  similar  mani- 

fin  ^^""!.  f  ^^™"S,  *o  yo^^"S  chickens,  Mr.  Spalding  con- 

dr^Tir'^'"'''  "  '''''''  ^  ^•'^^^  '^^«»  then/attempt  to 
dress  their  wings  when  only  a  few  hours  old-indeed  as  soon 
as  they  could  hold  up  their  heads,  and  even  when  denied  the 
use  of  their  eyes.  The  art  of  scraping  in  search  of  food, 
which,  If  anydnng,  might  be  acquired  by  imitation-for  a  hen 
with  chickens  spends  the  half  of  her  time  in  scratching  for 
wih^/  ""^^^'^''^^^f  ^"other  indisputable  case  of  instinct. 
Without  any  opportunities  of  imitation,  when  kept  ouite 

t^lff  -^T  '*";'.  ^'''^'  ^^"^^'^"^  ^^Sa^  t«  ««rape  win  from 
two  to  SIX  days  old.  Generally,  the  condition  if  the  ..round 
was   suggestive;    but  I  have  several  times  seen  the  S 

a  sZthTab^:..~^^  °'  '  '''''  °^  ^^^^°^«  ^--'  -^^  - 

In  this  connection  I  may  here  insert  an  interestin..  obser- 

Thomsol  FKS  'h"7  communicated  to  me  by  Dr.  ATen 
iiiomson,  f  .E.S.     He  hatched  out  some  chickens  on  a  carnet 

inclination  to  scrape,  because  the  stimulus  supplied  by  the 

to  caU  into  action  the  hereditary  instinct;  but  when 
s^inJeTtr  '^"""^'^^  "  ^^'^'  gravel  on  the  carpet,  and  so 
SedfatP^v  JPT/"^'  ''  customary  stimulus,  the  chickens 
immediately  began  their  scraping  movements 

-But  to  return  to  Mr.  Spalding's  experiments,  he  snys  — 
fT.,f         f»  example  of  unacquired  dexterity,  I  may  niention 
that  on  placmg  four  ducklings  a  day  old  in  the  opL  aii  for 


i  i    ■   ^ 

I     ' 


164 


MENTAL  EVOLUTION  IN  ANIMALS. 


!!     '!' 


i  iH 


tlie  first  time,  one  of  them  almost  immediately  snapped  at 
and  caugiit  a  fly  on  the  wing.     More  interestini,  however  is 
the  de]il)erate  art  of  catdiing  flies  practised  l.y  the  turkey 
When  not  a  day  and  a  half  ohl  I  observed  the  young  turkey 
already  spoken  of  slowly  pointing  its  beak  at  flies  and  other 
small  insects  without  actually  pecking  at  them.     In  doing 
this,  Its   head  could  be  seen  to  shake  like  a  hand  that  is 
attempted  to  be  held  steady  by  a  visible  effort.     This  I  ob- 
served and  recorded  when  I  did  not  understand  its  meanin^r 
J^orit  was  not  until  after,  that  I  found  it  to  be  the  invariable 
liabit  of  the  turkey,  when  it  sees  a  fly  .settled  on  any  ol))ect 
to  steal  on  the  unwary  insect  with  slow  and  measured  step 
until  sufficiently  near,  when  it  advances  its  head  very  slowly 
and  stendily  till  within  an  inch  or  so  of  its  prey,  which  is 
then  seized  by  a  sudden  dart." 

Mr.  Spalding  subseijuently  tried  similar  experiments,  with 
similar  results,   on   newly  born   mammals.     He  found,  for 
instance,  that  new-born  pigs  seek  to  suck  almost  immediately 
after  birth.     If  removed  twenty  feet  from  the  mother,  they 
wriggle  straight  back  to  her  guided  apparently  by  her  grunt- 
ing.    He  put  a  pig  into  a  bag  immediately  it  was  born,  and 
kept  It  m  the  dark  till  seven  hours  old,  and  then  placed  it 
outside  the  sty  ten  feet  from  its  mother.     It  went  straight  to 
lier  although  it  had  to  struggle  for  five  minutes  to  squeeze 
under  a  bar.     A  pig  blindfolded  at  birth  went  about  freely, 
though  tumbling  against  things.     It  had  the  blinder  taken 
off  next  day,  and  then  "  went  round  and  round  as  if  it  had 
had  sight,  and  had  suddenly  lost  it.     In  ten  minutes  it  was 
scarcely  distinguishable    from   one  that  had  had   sight  all 
along.  When  placed  on  a  chair,  it  knew  the  height  to  require 
considering,  went  down  on  its  knees,  and  leaped  down.      . 
One  day  last  month,  after  fondling  my  dog,  I  put  my  hand 
into  a  basket  containing  four  blind  kittens  three  days  old. 
The  smell  my  hand  had  carried  with  it  sent  them  puflin"  and 
spitting  m  a  most  comical  fashion."* 

Here  I  may  quote  an  observation  of  my  own  from  the 
succeeding  issue  of  "  Nature." 

"  Apropos  to  what  Mr.  Spalding  says  about  the  early  age 
at  which  the  instinctive  antipathy  of  the  cat  to  the  dog 
becomes  apparent,  I  may  state  that  some  months  ago  I  tried 
an  experiment  with  rabbits  and  ferrets  somewhat  similar  to 

Into  an  out- 


that  which  he  describes  v/ith  cats  and  dogs. 


•  Natttre,  vol.  xi,  p.  507. 


hi 


PERFECTION  OP  INSTINCT. 


1G5 


, 


house  winch  contained  a  doe  rabbit  with  averyyounrr  family 
I  turned  loo.se  a  ferret.  The  doe  ral.l.it  left  her  young  ones 
and  the  latter,  as  soon  as  they  smelled  the  ferret,  be^an  to' 
crawl  about  in  so  enerj^etic  a  manner  as  to  leave  no'doubt 
that  the  cause  of  the  commotion  was  fear,  and  not  merely 
motht!'*" "^  ""''"°  ^''''"'  ^^'"   temporary  absence  of  the 

With  reference  to  the  instinctive  endowments  of  this 
kind  in  kittens.  I  may  also  quote  the  followin-  which  I  find 
amon<?Mr.  JJarwin'sMSS:—  ^«-"  a  mm 

"The   many  cases  of  inborn  fear  or  ferocity  in  younc 
animals  directed  towards  particular  objects,  m  well  as  the 
loss  of  these  individualized  passions,  seems  to  me  extremely 
curious     Let  any  one  wlio  doubts   their  existence  give  i 
mouse   o  a  kitten  taken  early  from  its  mother,  and  which  has 
never  before   seen  one.  and  observe  how  soon   the   kitten 
growls  with  hair  erect,  in  a  manner  whoUy  different  from 
when  at  play  or  when  fed  with  ordinary  food.     We  cannot 
suppose  that  the  kitten  has  an  inborn  picture  of  a  mouse 
graven  in  its  mind.     But,  as  when  an  old  hunter  snorts  with 
eagerness  at  the  very  first  sound  of  the  horn,  we  must  sup- 
pose  the  old  associations  excite  him  almost  as  instantly  as 
when  a  sudden  noise  makes  him  start,  so  I  imagine,  with  the 
diflference  that  the  imagination  has  become  hereditary  instead 
of  being  only  fixed  by  habit,  the  kitten  without  any  definite 
anticipation   trembles  with  excitement  at  the  smeU  of  the 
mouse. 

The  only  other  observations  made  by  Mr.  Spalding  which 
^  IS  desirable  to  quote  are  those  by  which  he  proved  experi- 
mentally that  young  birds  do  not  require,  as  was  ordinarily 
supposed.   0  be  taught  to  fly.  but  fly  instinctively.     This  fact 
was  proved  by  keeping  young  swallows  caged  until  they  were 
fledged,  and  then  a  lowing  them  to  escape.     When  we  con- 
sider  the  complicated  muscular  co-ordination  required  for  fli-ht 
the  fact  that  young  birds  when  fledged  should  be  able  to°fly 
at  the  first  attempt  constitutes  another  remarkable  instance 
of  the  perfection  of  instinct.     Of  course  it  is  true  that  under 
ordinary  circumstances  the    parent  birds   encourage    their 
progeny  to  fly,  but  the  experiments  in  question  show  that 
Bucii  encouragement,  or  tuition,  is  not  necessary  to  enable  the 
young  birds  to  practise  the  art. 

But  it  is  among  insects  that  we  meet  with  the  most  re- 

•  Nature,  vol.  xi,  p.  554. 


'I  I 


^il  'i 


■  ?    f! 


Hi 


i  .: 


'Irej 


166 


MENTAL  EVOLUTION  IN  ANIMALS. 


?w«n?  !,  '^'^'-  ?\"''  *°  ^^«  °"^y  a  few.  Edaumur  and 
dr?  wmt^i^  Tl'^  '^"'  "r^"8  ^^^'  ^^  «^^°  «^  its  wings  are 
ftj'.M  .  °".f'u-?'°'''^/°^  construct  a  cell  as  efficiently  as 
the  oldest  inhabitant  of  the  h.ve.*  Numberless  insects  a  J 
can  never  have  seen  their  parents,  and  yet  they  perfom 
nstinctive  actions  perfectly,  though  it  maybe  onfyonce  in 
their  hfe-times-such,  for  instance,  as  the  Ichneumon  which 

sZlTll'rF'''  tl^\!^°dyof  a  larva  hidden  between  he 
scales  of  a  fir-cone,  which  it  can  never  have  seen  and  vpf 
knows  where  to  seek.f  '         ^ 

A  kind  of  insect  called  the  Bembex  conveys  food  to  it^ 

^Tde^I^^  r  f^l  "P  '"  ^  ^^"'  ^^^  ''  h^«  recentry  been 
^T  the  subject  of  some  interesting  experiments  bv  M 
iabre     Of  these  the  following  is  an  epitome  •-  ^ 

"  The  msect  brings  from  time  to  time  fresh  food  to  her 
young,  and  it  is  remarkable  how  the  Bembex  remembers  the 
entrance  to  her  cell,  covered  as  it  is  with  sand,  exacTlv  to  ou? 
eyes  like  that  all  round.  Yet  she  never  make  a  Sake  or 
loses  her  way.  On  the  other  hand  M.  Fabre  found  that  if  he 
removed  the  surface  of  the  earth  and  the  passage  thus  ex 

she  knew  H?r^  '''°^'"''  ^''  "T  °^'^P""g-  ^'  «^««^«  as  S 
child  Tnn  1?  '''  ''''''''y'  ^^^  *^^  P^««^ge,  but  not  her 
cniia.     Another  ingenious   experiment  of    M.  Fabre's  was 

S?l  thTf  f'^'f'tr-  ^^"^  ^^^^^  ''  -«l«-d  ii  an  earthen 
cell  through  which  at  maturity  the  young  insect  eats  its  way 
M  Fabre  found  that  if  he  pasted  a  piece'of  paper  round  the 

enitVZ'  J?K  "'  ™'"''^  ^^  '^'"''^  ^^-' gh  it,  but  if  he 
evenofnnlv'  f  ""r  P^P,^^  ^^«e'  ««  ^hat  there  was  a  space 
even  ot  only  a  few  hues  between  tlie  cell  and  the  paper  in 
tha   case  the  paper  formed  an  effectual  prison.     The^fnSnc^ 

'  had  nV"T'  '""f  ^.  ^V"  ^'''  through  one  enclosure,  but  5t 
had  not  wit  enough  to  do  so  a  second  tirae."t 

nf  oTwJ.^^'"'^!,*^''*  P^^^^P^  t^e  "lost  remarkable  instance 
of  all  that  can  be  quoted  from  the  insect  world  to  show  the 

whX^n7.  r^'^'T  i'^  ^^^ly-f'^^ed  instincts,  is  one 
which  IS  apt  to  be  overlooked-and  indeed,  so  far  as  I  know 
has  been  overlooked-on  account  of  its  frequency.     I  refer  to 

tot'.lwrr\^'^^-  '^  ^"''"^^'^'  ^'^  ^'^'^S  reference  to  a 
in  eot^.fhfr'^^^  ^^^^'^'  °f  life,  which  those 

insects  that  undergo  a  complete  metamorphosis  present  fuUy- 

!  ^^'"^y^"'*  Spenee,  loc.  cit,  vol.  ii,  p.  470.  t  Thid   i  n  1«;» 

J  Sir  J.  Lubbock,  Address  to  Entomol.  Soc.  1882  '  '  ^'       * 


IMPERFECTION  OF  INSTINCT. 


167 


formed  and  ready  for  complete  action  as  soon  as  the  imaoo 
escapes  from  its  pupa  stage.     The  difference  between  its  pr^e- 

""'T  IL^^  ^  ^^7^  ^""^  '^^  ^^w  li^e  as  an  imago,  is  as  great 
as  the  difference  between  the  lives  of  two  animals  belong- 
ing to  two  different  sub-kingdoms;  and  the  complete  adapta- 
tion which  all  the  new  class  of  instincts  exhibit  to  the 
requirements  of  this  new  life,  is  quite  as  remarkable  as  is  the 
adaptation  of  the  new  structures  to  the  same  requirements. 

Imperfection  of  Instinct. 

Jf\f}}^^'st  give  a  few  cases  to  show  that  instinct  is  not 
an  mfaUible  guide  to  action,  and  for  this  purpose  shaU  choose 
aberrations  of  those  instincts  which  we  should  expect  to  be 
most  hxed  because  of  most  importance  to  the  weU-being  of 
the  animals  or  their  progeny— I  mean  the  instincts  of  pro- 
pagation and  the  procuring  of  food. 

The  flesh-fly  (Musca  carnaria)  deposits  its  eggs  in  the 
flowers  of  the  "  carrion  plant "  {Stapclia  hirsuta\thB  smell 
of  which  resembles  that  of  putrid  meat,  and  so  deceives  the 
ny.  _  bimi  rly,  the  house-fly  has  been  observed  to  deposit 
eggs  in  snuL.f  ^ 

Again,   the  Eev.  Mr.  Bevan  and  Miss  C.  Shuttleworth 
write  me  independently  that  they  have  seen  wasps  and  bees' 
visiting  representations  of  flowers  upon   the  wall-paper  of 
rooms;  and  Tre^eUian  saw  the  same  mistake  made  by  the 
sphmx-moth  I     Swamson  in  his  "  Zoological  Illustrations  " 
gives  an  analogous  case  in  a  vertebrat  d  animal;  an  Austra- 
lian parrot,  whose  food  is  taken  from  the  flowers  of  the 
Jiucalyptus,  was  observed  endeavouring  to  feed  on  the  repre- 
sentation of  flowers   on   a    cotton-print    dress.      Likewise 
Professor  Moseley,  F.R.S.,  informs  me  that  he  has  noticed 
honey-seeking  insects  mistake  for  flowers  the  bright  coloured 
salmon  flies  stuck  in  his  hat  while  fishing;  and  Mr  F  M 
Burton  writing  to  "  Nature  »  (xvii,  p.  162)rsays  that  he  "has 
observed  the  humming  bird  hawk-moth  {Macroglossa  stellar 
tor^^m)  mistake  artificial  flowers  in  a  lady's  bonnet  for  real 
ones.    Still  more  curiously,  the  naturahst  Couch  observed  a 

«  ^^'  ?'''"T'?'  £'"'"°'«^'«.  i.  §  16,  art.  11.    Also  Kirby  and  Spence.  he  c!t 
u,  469  who  state  the  fact  on  the  authority  of  Dr.  Zinken  ' 

t  Zmken,  in  Germar.  Mag.  der  Unto.,  Bd.  I,  abth.  4,  §  189. 

J  See  Houzeau,  loc.  cit.,  I,  210.  >  s    "i«. 


,HI 


•  i-^  1  ■;*'' 


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111^ 


If 


i; 


t  •  ,: 


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, 


hi 


V.}, 


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Miil 


168 


MENTAL  EVOLUTION  IN  ANIMALS. 


"!l,f''''?^®  ^  sea-aneraone  (realia  crassicornis),  which  wag 

into  the  centre  of  the  disk,  "  and  though  it  struggled  a  good 
deal  to  get  free  was  retained  tiU  it  was  drowned  and  was 

tvm,r  thl  ,*^'^  r't'''  °^  ^^«  humble-bee  attempt  to 
a  remarlnhl'f '  ''^/'^  *^^'  """^^  ^"^^^'  ^PP«^^«  ^°  «°««titute 
bee  Teo-n'rif  "^  imperfect  instinct.     Again,  Huber  saw  a 

to  BiPOP.  V  \  "'  ^  T".^  ^"'"'*^^°°'  ^^d  °t^^«r  bees  tear  it 
to  pieces.  Bees  have  also  been  observed  to  collect  rye-flower 
when  damp  instead  of  pollen.f  "  Pollen-getting,  accordinTto 
Gebien,  is  the  weak  point  in  the  characte^r  of  bees;"  fo^th  s 

^^t^  ff"""'"''  ^P-  '^^  '^'''  '^'^y  "%  up  useless  hoards  ofit 
I  nt  n  '!f]  '^"l  Z  """"Smenting  every  year,  and  this  is  the  only 
point  on  which  they  can  be  accused  of  want  of  prudence." 

numW  ?rr"'  ?^^  ^'^''  '""^'"^  ^  brief  Record  of  a 
number  of  observations   on   ants   (F.   rufa)   carrying  pupa 

itourTf  '  ^T  ""?  'PP^^^^^^^  "«^1^««  expenditure  of 
labour,  far  away  from  the  nest,  and  even  up  trees.     He  tried 

taking  away  the  skms  from  some  of  the  cariders,  and  replacing 

l!^  T"  *^'  ^''^'  *^^^'^*  ^°^«  that  happened  to  fall  in 
with  them  again  carried  tliem  off.  This,  as  the  notes 
observe,  appears  to  be  a  case  of  "blundering  instinct;"  and 
w!T'  epitliet  may  be  appliec.  to  mistak'es  made  by  the 
^fnl/  %r^'  '^'''^'^  ^y  ^^''  Moggridge,  which  carefully 
TnLV}l7  ^'^''''■''  ^^^\g«ll-^PPle«  of\  small  species  o^ 
Ci/mps,  clearly  imagining  that  they  were  nuts ;  and  also 
nnder  a,  simihtr  delusion,  stored  small  beads  whSi  Mo '-' 

faltSiiigfSd:^''  *"'  '^"^  ^^^^^^^>  -^"-'^d  -  thei. 

Among  Birds  we  find  mistaken  instinct  exhibited  by  the 

Z^ZT'"'''   u^!  '^^  ^-^  ^"  '^'  '^^^  nest,  withM 

eS  tt  oS    '^\r  '^  '^'  y°^"«  ^''^'  ^ill  ^ft^rwards 
eject  ttie  other.     In  the  same  category  we  mav  nlaop  thp 

sCauTiXf  "'"PP;?*  "'  ""r  ^86'  on  the  paHf Zt-h* 
f^  1^  ?     .  frequently  mistaking  a  lai^er  and  unfamiliar  bird 
for  a  hawk,  as  shown  by  their  mobbing  it;  and  numberless 
maSrn r'T".-"^  ^jven  of  mistaW  instinct  i„  tie 

SSL  m:S::&::  ot  "'^""°"  "^  ""^-'^^'^  ^''^'• 


niPERFECTION  OF  INSTINCT.  169 

by  Mr  Darwin^n  f  ho  A         }-^  shrewmouse,  also  mentioned 

InteUirrence  » Tn  S^Qwf*  •  *"'  ^  «^erve  in  "Animal 
praSd  hv  if  1  '*•'  lu^''^  witnessed  the  mode  of  capture 
S  the  ibbir-S.;^  ^^'."P'^  ^'^'^'  ^"d  i^  «°"«i«ts  "merely 

behind  unS  t.n,°i  iT  ^^°"?'  ^^^^  ^^'  ^^^^^l  toddling 
Denmd,  until  tamely  allowing  itself  to  be  overtaken 

^r^l  i7         ','"'•  ''°"'^«'''  ■^'''<=''  time  would  doubtless 
remedy  rf  weasels  were  sufficiently  numerous  in  relation  to 

*p~rtlt/  or^rff  r"  't''- '"  ?™  -^u-l'lectionth: 
pSSnemyr  °"  '"'  "'"™'  °'  ^^^"^  f™""  *is 

mi"Se^™Sr,'r°''  f  .*'  imperfection  of  instinct 
VIZ.,  that  although  weU  established  instincts  are  as  a  rule 

\^!      IS  sumcient  to  lead  the  instinct  astray     It  is  also  nf 

T'tt^""'  5?  °°''  ^^"'  ^^^^"«  **^  b«  ^  compLentarytuth 
vu..  that  small  variations  taking  place  in  the  or^ar ism  itself 
when  not  m  normal  converse  with  its  environment  Z  S 

are  not  at  first  at  home  in  them),  but  is  brou^it  ou  ?n  a  mueh 
"Uefore  passing  to  the  theory  of  instinct,  it  may  be 


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II 


170 


MENTAL  EVOLUTION  IN  ANIMALS. 


M 


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worthy  of  remark  that,  unlocked  for,  I  met  with  in   the 
course  of  experiments    some  very  suggestive,  but  not  yet 
sufliciently  observed,  phenomena ;  which,  however,  have  led 
me  to  the  opmion  that  not  only  do  the  animals  learn,  but  they 
can    also  forget— and  very  soon— that  which  they  never 
practised.    Further,  it  would  seem  that  anv  early  interference 
with  the  established   course  of  their  lives  may  completely 
derange  their  mental  constitution,  and  give  rise  to  an  order  of 
manifestations,  perhaps  totally  and  unaccountably  different 
trom  what  would  have  appeared  under  normal  conditions. 
Hence  I  am    inclined   to  think  that  students  of    animal 
psychology  should  endeavour  to  observe  the  unfoldin^r  of  the 
powers  of  their  subjects  in  as  nearly  as  possible  the  ordinary 
circumstances  of  their  lives.     And  perhaps  it  may  be  because 
they  have  not  all  been  sufficiently  on  their  guard  in  this 
matter,  that  some  experiments  have  seemed  to  tell  against  tlie 
reality  of  instinct.     Without  attempting  to  prove  the  above 
propositions,  one  or  two  facts  may  be  mentioned.     Untauoht 
the  new-born  babe  can  suck— a  reflex  action ;  and  Mr.  Her- 
bert Spencer  describes    all  instinct  as    'compound    reflex 
action  ; '  but  it  seems  to  be  well  known  that  if  spoon-fed,  and 
not  put  to  the  breast,  it  soon  loses  the  power  of  drawin^^  milk 
Similarly,  a  chicken  that  has  not  heard  the  call  of  the  mother 
until  eight  or  ten  days  old  then  hears  it  as  if  it  heard  it  not. 
1  regret  to  find  that  on  this  point  my  notes  are  not  so  full  as 
1  could  wish,  or  as  they  might  have  been.     There  is,  however 
an  account  of  one  chicken  that  could  not  be  returned  to  the 
mother  when  (?  until)  ten  days  old.     The  hen  followed  it,  and 
tried  to  entice  it  m  every  way;  still  it  continually  left  her  and 
ran  to  the  house  or  to  any  person  of  whom  it  caught  si^ht 
Ihis  It  persisted  in  doing,  though  beaten  back  with  a  small 
branch  dozens  of  times,  and  invlecd  cruelly  maltreated.    It  was 
also  placed  under  the  mother  at  night,  but  it  again  left  her  in 
the  morning.     Something  more  curious,  and  of  a  diff'erent 
kind,  came  to  light  in  the  case  of  three  chickens  that  T  kept 
hooded  until  nearly  four  days  old— a  longer  time  than  ^  lyl 
have  yc^  spoken  of     Each  of  these   on  being  unhooded 
evinced  the  greatest  terror  of  me,  dashing  off  in  the  opposite 
direction  whenever  I  sought  to  approach  it.     The  table  on 
which  they  were  unhooded  stood  before  a  window,  and  each 
in  Its  turn  beat  against  the  glass  like  a  wild  bird.     One  of 
them  darted  behind  some  books,  and,  squeezing  itself  into  a 


IMPERFECTION  OF  INFsTINCT. 


171 


comer,  remained  cowering  for  a  Imgth  of  time.    We  mi=ht 

f^s3    but  theTw'Y^"'-'"^  ''Tf'"^  exceptional  wflS- 
ness ,  but  the  odd  fact  is  enough  for  my  present  numntiP 

Whatever  might  have  been  the  meaning  of  Lrmarked^cCe 

m  their  mental  constitution-had  the^been  unCoded  on  the 

previous  day  they  would  have  run  to  me  instead  of  from  me 

-It  could  not  h^ve  been  the  effect  of  experience    iSm^s? 

have^  resulted  wholly  from  changes  in  theFr  Twn  irgaZ- 

keenw'T'"*^"^  ^r  ^^"^^^"^  *"^^  ^he  experiment  of 
keeping  young  duckhngc  away  from  the  water  for  several 
days  after  they  were  hatched;  on  then  bringing  them  to  a 
pond  they  showed  as  much  dislike  to  the  v^atfr  as  V^n' 

and  partjcu  arly  the  tendency  which  is  thus  iitduced  among 
hen  I  nL^tTp'^'- ^"?^''^"°  ^"^  other  habits  of  tfif 
brbr  /w  s/;Ld  fT^^'w  ^r''""'^^  P"^^^^«^^d  article 
by  UT  J  W.  Stroud  of  Port  Elizabeth,  who  has  devoted  a 
good  deal  of  attention  to  the  subject  of  caponizi  i.  -1 

Aristotle,  more  than  two  tliousand  years  a<ro  tells  us  of 

Libtx  49I  Ppf  ^T'  '''  ^!"  ^^^^^^  °f  '  hen/'VHistln 
i.ib.  IX,  42.)   Plmy,  too,  speaks  of  the  motherly  cure  bestowed 

by  a  cock  on  chickens.     '  He  did  everything  for  them '  s^vs 

he,  'Ike  to  the  very  hen  that  hatched  them,  aid  erased  to 

crow.'     (<  Phny  Trans.'  i,  299.)     Albertus  Magnus  witnessed 

the  same  thing;  a.id  /Elian  ('Hist.'  iv,  29)  mentions  a  cock 

which  on  the  death  of  the  hen  while  hatching,  took  to  ?he 

(in   Lay  s  W  illoughby's  Natural  History '), '  We  have  beheld 
more  than  once,  not  without  pleasure  and  admiration,  a  Spon 
u/mging  up  a  brood  of  chickens,  like  a  hen  clucking  o^er  them 
feeding  them,  and  brooding  them  under  his  win .«  with Ts 
much   care  a  id  tenderness  as  their  dams  are  went  to  do ' 

Once  accnstomeu  to  this  office,'  says  Baptista  Eosa  ('Ma-na 
:N-aturalis  iv,  ,.f^), .«  Capon  will  never  abandon  it,  but  when 
one  orood  ..  grown  up  another  batch  of  new  v  hatched 
ch  ckens  may  bo  put  to  him  and  he  will  be  as  kind  to  tJ lem 
and  take  as  much  care  of  them  as  of  the  first,  and  so  S 
succession.'    lleaumur  ('Art  de  Faire  Eclore.'  ton.  ii  p  8)      ■ 


m  * ' 


H!J 


tn 


!  f 


172 


MENTAL  EVOLUTION  IN  ANIMALS. 


^  o^K'  ^°  ''<^-      (See    also    '  Cotta-e  Gardener.'    1  fifio 


^%fef  ^0  sit.     (See    also 
p.  o/y.  ""j 

Spn!nf  •;       ^  ^"^"^  repeatedly  to  suck  three  or  four  other 

D  201  ^Dr 'Z"'"'"''"^"'^*'.  ^  von  Paraguay" 

StLLncV  wlf^^^^^  '\'  ^'^^'™^  ^^''^^^^s  instance^of 

retrd%?tre':iri  h'^  ^  ¥^  ^^^^^^  -'j^stnce'ot' 
one  occasion  aT^  l^f  ^'"«  T^'^  ^^  ^^P^^^^^^'  ^"^  ^^^-^  on 
and  X17Z  T  '^  ^""V"*  ^^^^  pregnant  when  captured 
vonn^  ^hn.  ,•  '°"^f.T?"^  ^^  ^'''  N^^ed^'  brought  fortli  her 
wS  f    1    ^"^niediately  afterwards  devoured  them     TWs 

weU  rooTed  tlrJ^  'f  '^T.  ^^"^^^^^^  ^^°-  that  even  To' 
well  rooted    an  instinct  as  the  maternal  mav  be   crve'itW 

the''cld\'^'  '""^V^^T^  ^y  ^^^^  ^  f^-  monthfof  Chan  -e  1'^ 

domestf  Sow  .e  If"  '^T'^1  '^^^«  ^^  ^^^  ^^^^  of  the 
uoraesuc  feow,  pcu  Mice,  and  other  animals  exnosed  tn  tha 

influence  of  domestication  are,  of  course,  v  ry  coCmon         " 

the    'enevaT.^  ''''  f  '  i"\^s'°  ^'^"^  ^"^^^^^^  "^^^'^^^^^  ^  Prove 
.*atioilir?n  '^  '  '^"^  derangement  of  instinctive  o^ani! 

converse  w^tl    L         ^^''''  ""''  ^^^""'^^  ''^'''  '^  ^e  in  nomal 
converse  with  its  environment.     But  I  mav  here  addnPP  « 

organization   m    an   animal   which  was   apparently  in   aH 

St:  "t^ntThrr"  ^'''' ''?  environrnTaJfd  tMs  t 
insanitv  Bnf  nuJ  it  may  properly  be  regarded  as  a  case  of 
insanity.     But  although  perhaps  pathological  in  nature  it  i, 

S~The"  U^^^^^^^  1  ~-  thelmperfectnofin! 
Btmct~the  only  difference  between  it  and  the  cases  previously 


{  i 


IMPERFECTION  OF  INSTINCT.  173 

oftt^erif '"lh„"  '»:  """^Si-g  onuses  being  internal  instead 
01  external  Ihe  case  was  communicated  tome  bv  »  1,,!,, 
who,  from  Its  peculiar  nature,  desires  me  tr,^iti,Li.  ^'' 
name,  but  I  quote  the  account  in  WowTwori:!-""  ""' 

houseitrs  :£  a';r"HeTnV.;*:ttJt"T"^^^^ 

tcr'lbe'"""'  '''  ™"""  "'  *^  Atuation'l  am  about  to 

„„,:'i  ^°  ^™™*™''y  whatever  was  remarked  in  his  conduct 
unt  1  one  day  I  chanced  to  pick  up  somewhere  in  fh»  ^Si 

I  Sunt?tt''  of  the^ordina'ry  bro™Ton°dt,fp  oa 
1  nung  It  into  the  yai-d,  where  it  fell  iimnediatelv  bplow  tl!a 
pigeon-house.     Tliat  instant  down  flew  mLSio,  ^^^^ 
my  no  small  astonishment  commenced  a  s^er     7.^^S 
evidently  domg  homage  to  the  bottle.     He  strutted  round  and 
round  It  bowing  and  scraping  and  cooing  and  perforWth^ 
most  ludicrous  antics  I  ever  beheld  on  the  parrof Tn^ena 
moured  pigeon.     ...    Nor  did  he  cease^  these  perform" 
ances  until  we  removed  the  bottle ;  and,  which  prov'drat  tWs 
singular  aberration  of  instinct  had  become  a^fiLd  delus  on 
M'henever  the  bottle  was  thrown  or  placed  in  fhp  vTrl?       ' 
matter  whether  it  lay  horizontally  o'rw^s  ^"aced  ^vv^^Z 
the  same  ridicu bus  scene  was  enacted ;  at  that  moment  ^ 
pigeon  came  flying  down  with  quite  as  great  alacrTy  as  then 
his  peas  were  thrown  out  fo?  his  diunpr   TnnnZ^       i,- 
antics  as  long  as  the  bottle  reiLu^Vt  ?    SometmeTthi" 
would  go  on  tor  hours,  the  other  meml.ors  of  hlfamX  trS 
ing  his  movements  with  the  most  contemptuoi  Serened 
and  taking  no  notice  whatever  of  the  bottle.     At  last  it 
became  the  regular  amusement  with  which  we  entertained 
our  visitors  to  see  this  erratic  pigeon  makinTlove  to  the 
interesting  object  of  his  affections,  and  it  was  "an  entertain 
ment  which  never  failed,  throughout  that  sumnL  at  least" 
Before  next  summer  came  round  he  was  no  more" 

It  is  thus  evident  that  the  pigeon  was  affected  with  somp 
strong  and  persistent  monomank  with  regard  to  hi  parti  ukr 
object.     Although  it  is  well  known  that  insanity  Tnot  an 

met  with  of  a  conspicuous  derangement  of  the  instinctive 
a^  Oistingmshed  from  the  rational  faculties-unlessSe^ 


m    ■'(. 


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174 


MENTAL  EVOLUTION  IN  ANIMAL3. 


they  do  in  man  ^'"'"''"  ""^  taquently  than 

general  head  „f"ImX  ''^'  ""^^^  ^^^ 

two  very  differ^ent  cTaS  o  ^om^^^^^^^^^  l^^^^^^ 

be  imperfect  because  thev  have  ^t  vpf  ?..  '"'^  ""^^ 
developed,  or  they  may  appear  lo  be  imnp,?  ^^'^"'P^'^'^^ 
completely  answerina  to  ^nmpi!        imperfect  because  not 

»e?r  \s:;TaS  ^"^^^i:!^- 

Ihus    to  quote  from   "  Animal  Intelligence  '' ■_"  l.w„, ,?' 
these  usete^mo„r  et  o»"  iSt  SS'^It" V°  .""^ 


Ik 


,1 

I  "I 


i 


IMPERFECTION  OF  INSTINCT.  175 

instincts  YutVhatvtTl,»J   ^'    ■ '"'  P™"'™!^  "^eful 

time-namelTr  their  if rvlT     "'^''i^^  ^^^'  "^^^^  P^°«table 
that  in  m^y  Aspects  Tt  seemi  f n'  y.'^'^  ^^^te-f rom  the  fact 

^^^eeifi::::^^^        ^-^^^ped  to  a 

.^ites^'i''  '"^'  '"^^  °"^  ^^^^^  illustration,  Mr.  Spalding 
"  Another  suggestive  class  of  phenomenn  flinf  ft.n       ^ 

first,  I  ieliZ,  it  S  ev"    seen     if  "^'"m""  '?  ?"">-*" 
aceurate  general  sltem^n   I  c^^TiVe™   th';  Xv  f'  ""'' 

=i^L-?rt?S-ir^^^^^ 

S;S;3et'..'''^-™'^"''-.-«'K 

Mr  IZS'  l;"'^,''''™^  .the  life-time  of  the  indivi<l„nl 

instincts  of  the  rhilrf    T?  ^  i"^  •'"'^'''^'^  '"  ^^^«  developing 
the  head  in  «n         •, .    ^'"''  ^^^  instance,  tlie  balancing  of 


'    T 


■1 

( ■ 

i 

it 

1  :! 


178 


MENTAL  EVOLUTION  IN  ANIMALS. 


about  SIX  weeks*    He  says  that  the  child  first  acoiclentallv 
finds  the  comfort  of  the  attitude,  and  so  adopts  it  more  and 
more  constantly  until  through  habit  it  becomes  instinctive 
He  also  gives  exactly  parallel  facts  in  the  case  of  learning  S 
creep,  sit,  stand,  walk,  &c.t  ^^^^mng  w 

Among  animals  in  a  state  of  nature  we  may.  I  think 
regard  all  instincts  which,  so  far  as  w.  con  see,  are  trivial  or 
useless,  as  instincts  which  are  imperfect,  in  that  they  do  not 

ZZVlf"^  l^'^u'-''  "'"^^  ^"  ^^«  ^"""^^1«'  Present  condi. 
tions  of  hie.     Such  mstmcts  are  not  very  nnmcrous  and  n., 

Mr  Darwin  observes  in  the  Appendix,  they  may  be  quoted 
as  objections  to  his  theory  of  the  devebpmJnt  of^iastiSct  by 
natural  selection  I  shaU  subsequentl/ consider  thsdilli^ 
cu  ty,  but  here  I  have  only  to  note  the  fact  that  insMncis  of 
this  apparently  purposeless  kind  occur,  and  that,  and  pur- 
poseless,  they  are  imperfect.  Such,  for  instance  is  th« 
instinct  of  a  hen  cackHngwhen  she  has  laid  an  e^  the  co  k- 
pheasant  crowmg  when  going  to  roost,  cattle  and' elephants 
goring  their  sick  or  wounded  companions,  sundry  ins  incta 
connected  with  excrements-such  as  burying  them  n  ea  i 
always  depositing  them  in  the  same  place,''&c.--and  ot  e^ 
cases  mentioned  by  Mr.  Darwin  in  the  Appemlix 

But  the  most  important  class  of  considerations  for  us  is 
one  to  which  the  foregoing  may  be  said  to  lead  up  Ve 
have  seen  that  if  instincts  have  been  developed  by  evolution 
we  should  expect  to  find  cases  in  which  they  are^in  pro  ess 
of  evolution  or  not  yet  perfect ;  and  we  have  also  ^een  that 
this  expectation  IS  realized.  Now  in  so  far  as  instinct  requirea 
to  be  mixed  with  intelligence  in  order  to  be  effective  itis  as  an 
instinct  imperfect ;  it  is  as  an  instinct  in  course  of  format  on 
or  at  any  rate  not  perfectly  adapted  to  the  possible  0^0^- 
stances  of  life.     Therefore   all   cases  of   the   educatfon^f 

"S"tnVot'^^'^'^r-7-'^r  ^^  ^^^  indivrdrafoTtle 
race— tall  to  be  considered  m  the  present  'connection     TJia 

consiaeration  of  this  subject,  however,  lands  us  directly  in 
?n!3  ^        ^'^'\  ^^?.''  V  *^"  ^^^^S"^  and  development  of 


OBIGIN  AND  DEVELOPMENT  OF  INSTINCTS,  177 


CHAPTER  XII. 

Instinct  (continued). 
Origin  and  Development  of  Instincts. 

I.  The  first  mode  of  origin  "consists  in  natural  selection 
or  survival  of  the  fittest,   continuously  presorvina  actio"' 

Tenet  t^f  "T  ""IfiFf'  ^''  ^'^^PP-  ''  ^-«  btn  or- 
benefit  to  the  animals  which  first  chanced  to  perform  them 

Thus,  for  instance,  take  the  instinct  of  incubation.      It  is 

quite  impossible  that  any  animal  can  ever  have  kept  its  e-cg 

warm  with  the  intelligent  purpose  of  hatching  out  their   Sn! 

tents,  so  we  can  only  suppose  that  the  incubating  instinct 

ttf  ?o  fh^™'^^°'i'l"""^^'^^^  «^°^^"«  '^^'  kind^f  aten' 
IZ  M  ,'\'  '"^"  '^^''^  ^^  fi"^  <^°  ^«  frequently  shown  by 
cold-blooded  animals.  Thus  crabs  and  spiders  carry  aboS 
their  eggs  for  the  purpose  of  protecting  them:  and  if  as 
animals  gradually  became  warm-blooded,  som^' species  'for 

iX  abL/n^'fi  ""'"^^  ^T  ^''°°^'  incidental  to  the  car- 
rying about  of  the  eggs.  Consequently,  as  the  impartin-  of 
heat  promoted  the  process  of  hatching,  those  indiv  duals 
which  most  constantly  cuddled  or  brooded  o^er  heir  e^s 
would,  other  things  equal,  have  been  most  successful  7n 
rearing  progeny;  and  so  the  incubating  instinct  would  be 

thTmTter^''°"'  '^"'  '""  ^^""^  ^^^^  ^"^  ^^  W°c'  in 

.«•  ¥"  V^?  f  ^^^"^  """^^  °^  *^"gin  is  as  follows:— Bv  the 
SnalfvSi-'"  ««^«e««i^e  generations,  actions  which  were 
originally  intelligent  become,  as  it  were,  stereotyped  into  per- 

tanlcT'"'^  ^'""^  "^^  "^'^  "^"^"^^  ^'^  "Instinct."  in  the  Enc^clopcedia  Bri. 


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MENTAL  EVOLUIION  IN  ANIMALS. 


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manent  instincts.  Just  as  in  the  life-time  of  the  individual 
adjustive  actions  which  were  originally  intelligent  may  by 
Irequent  repetition  become  automatic,  so  in  the  life-time  of 
the  species  actions  originally  intelligent  may,  by  frequent 
repetition  and  heredity,  so  write  their  effects  on  the  nervous 
system  that  the  latter  is  prepared,  even  before  individual 
experience,  to  perform  adjustive  actions  mechanically  which 
m  previous  generations  were  performed  intelligently.  This 
mode  of  origin  of  instincts  has  leen  appropriately  called  the 
"  lapsing  of  intelligence."* 

^  For  the  sake  of  subsequent  reference,  I  shall  allude  to 
instincts  which  arise  by  way  of  natural  selection,  without  the 
intervention  of  inteUigence,  as  Primary  Instincts,  and  to 
those  which  are  formed  by  the  lapsing  of  intelHgence  as 
Secondary  Instincts. 

Let  us  now  consider  the  reasons  which  d  'priori  lead  us  to 
assign  the  probable  origin  of  instincts  to  these  principles, 
laking  first  the  case  of  primary  instincts,  these  reasons  may 
be  briefly  rendered  thus : — 

(1.)  Many  instinctive  actions  are  performed  by  animals 
too  low  in  the  scale  to  admit  of  our  supposing  that  the  adjust- 
ments which  are  now  instinctive  can  ever  have  been  intel- 
ligent.    (2.)  Among  the  higher  animals  instinctive  actions 
are  performed  at  an  age  before  intelligence,  or  power  of 
learning  by  individual  experience,  has  begun  to  assert  itself, 
(d.)  Considering  the  great  importance  of  instincts  to  species 
we  are  prepared  to  expect  that  they  must  be  in  large  part 
subject  to  the  influence  of  natural  selection.     As  Mr.  Darwin 
observes,  "  it  wiU  be  universally  admitted  that  instincts  are 
as  important  as  corporeal  structures  for  the  welfare  of  each 
species  under  its  present  conditions  of  life.     Under  changed 
conditions  of  life  it  is  at  least  possible  that  slight  modifica- 
tions of  instinct  might  be  profitable  to  a  species ;  and  if  it 
can  be  shown  that  instincts  do  vary  ever  so  little,  then  I  can 
see  no  difiiculty  in  natural  selection  preserving  and  con- 
tinually accumulating  variations  of  instinct  to  any  extent 
that  was  profitable." 

That  instincts  may  arise  by  way  of  lapsed  intellitrence  is 
rendered  probable  d  ipriwi  by  all  the  facts  which  show  the 
resemblance  between  instincts  and  intelligent  habits.  To 
take  only  a  few  of  these  facts  for  the  present  purpose,  I 

•  By  Lewes,  see  Problems  of  Life  and  Mind. 


ORIGIN  AND  DEVELOPMENT  OF  INSTINCTS.  1*79 

cannot  do  better  than  confine  myself  to  making  a  quotation 
from  Mr.  Darwin's  MSS  ;  for  this  will  show  how^  deep  seateS 
and  detailed  is  the  resemblance  between  habit  and  instinct 

'In  repeating  anything  by  heart,  or  in  playing  a  time 
ZTl.TJm'n^^'ii  if  «^^"Pt«d,  it  is  easy  to  back  a  little 
but  very  difficult  suddenly  to  resume  the  thread  of  thoucrht 
or  action  a  tew  steps  in  advance.   Now  P.  Huber  has  described 
a  caterpillar  which  makes  by  a  succession  of  processes  a  very 
complicated  hammock  for  its  metamorphosis;  and  he  found 
that  If  he  took  a  caterpillar  which  had  completed  its  ham- 
mock up  to,  say  the  sixth  stage  of  construction,  and  put  it 
into  a  hammock  completed  up  only  to  the  third  stage,  the 
caterpillar  did  not  seem  puzzled,   but  repeated  the  fourth 
htth,  and  sixth  stages  of  construction.     If,  however,  a  cater- 
pillar was  taken  out  of  a  hammock  made  up,  for  instance,  to 
the  third  stage,  and  put  into  one  finished  to  the  ninth  staae 
so  that  much  of  Its  work  was  done  for  it,  far  from  feeliSg 
the  benefit  of  this,  it  was  much   embarrassed,   and   even 
forced  to  go  over  the  already  finished  work,  starting  from  the 
third  stage  which  it  had  left  off  before  it  could  complete  its 
Hammock.     So,  again,  the  hive-bee  in  the  construction  of  its 
comb  seems  compelled  to  follow  an  invariable  order  of  work 
M  Fabre  gives  another  curious  instance  how  one  instinctive' 
action  invariably  follows  another.    A  Sphex  makes  a  burrow 
flies  away  and  seeks  for  prey,  which  it  brings,  paralyzed  b^ 
having  been  stung,  to  the  mouth  of  its  burrow ;   but  alwavs 
enters  to  see  that  all  i.  right  within  before  dragging  in  Us 
prey;    whilst  the  Sphex  was  wit^un  its  burrow    M  Fabre 
removed  the  prey  to  a  short  distance ;  when  the  Sphex  came 
out  t  soon  found  the  prey  and  brought  it  again  to  the  mouth 
of  the  burrow;   but  then  came  the  instinctive  necessity  of 
reconnoitering  the  just  reconnoitered  burrow;   and  as  often 
as  M.  Fabre  removed  the  prey,  so  often  was  all  this  gone 
ZZn^Tl  'l^^^^  *^'  unfortunate  Sphex  reconnoitered  its 
burrow  forty  times  successively  !    When  M.  Fabre  altogether 

T^'^A  fi^  P''^'.'^'  ^P^^^'  i^^^^^d  °f  searching  for  fresh 
prey  and  then  making  use  of  its  completed  burrow,  felt  itself 

and  befor/'T^'^  '^  ^'"^^^  the  rhythm  of  its  insttcl 
ana  before  making  a  new  burrow,  completely  closed  up  the 
0  d  one  as  If  it  were  all  right,  although  in  fact  utterly  useless 
as  containing  no  prey  for  its  larva.*  ^ 

•  Anf^.  des  Sci.  Nat.,  4  ser..  tome  vi,  p.  148.    With  respect  to  Bees,  .ee 


i 


:\   'X 


180 


.*,•!  ; 


I'i  i 


MENTAL  EVOLUTION  IN  ANIMALS. 


'II » 


'     i- 


r  *'"" 


^  In  another  way  we  perhaps  see  the  relation  of  habit  and 
instinct,  namely  in  the  latter  acquiring  great  force  if  practised 
only  once  or  twice  for  a  short  time ;  thus  it  is  asserted  that 
It  a  calf  or  infant  has  never  sucked  its  mother,  it  is  very  much 
easier  to  bring  it  up  by  hand  than  if  it  has  sucked  only 
once.  So  again  Kirbyf  states  that  larva,  after  having  '  fed 
tor  a  time  on  one  plant,  will  die  rather  than  eat  another, 
which  would  have  been  perfectly  acceptable  to  them  if  ac- 
customed to  it  from  the  tirst.' " 

Such,  then,  are  some  of  the  d  priori  reasons  for  believing 
that  instincts  must  have  arisen  from  one  or  other  of  these 
two  sources— natural  selection  or  lapsing  intelligence ;  it  now 
remains  to  prove,  a  posteriori,  that  they  have  so  arisen  I 
may  first  give  a  brief  sketch  of  how  this  proof  ought  "to 
proceed.  ° 

The  proof,  then,  that  instincts  have  had  a  primary  mode 
of  origin  re(juires  to  show : —  '         ~ 

I.  That  non-intelligent  habits  of  a  non-adaptive  character 

occur  in  individuals. 

II.  That  such  habits  may  be  inherited. 

III.  That  such  habits  may  vary. 

J7'rrF^^^-7'^®"  *^^^^^^y  ^^^  variations  may  be  inherited. 

V.  Ihat  if  such  variations  are  inherited,  we  are  justified 
in  assuming,  in  view  of  all  that  we  know  concerning 
the  analogous  case  of  structures,  that  they  may  be  fixed 
and  intensified  in  beneficial  lines  by  natural  selection. 

The  proof  that  instincts  have  had  a  secondary  mode  of 
origin  requires  to  show : — 

VI.  That  intelligent  adjustments  when  frequently  per- 
formed by  the  individual  become  automatic,  either  to 
the  extent  of  not  requiring  conscious  thought  at  all, 
or,  as  consciously  adjustive  habits,  not  requiring  the 
same  degree  of  conscious  effort  as  at  first. 
•  VII.  That  automatic  actions  and  conscious  habits  may 
be  inherited. 

Primary  Instincts. 
^     Proceeding,  then,  to  consider  these  sundry  heads  of  proof, 
It  IS  easy  to  establish  Proposition  I,  inasmuch  as  the  fact 

Kirby  and  Spence,  Entomology,  vol.  i,  p.  497.     For  the  hammock  caterpiUar. 
Bee  Mem.  Soc.  Phys.  de  Qenive,  tome  vii,  p.  154.  ^ 

*  Zoonomia,  p.  140.  f  Intro,  to  Entomol,  vol.  i,  p.  391. 


_, — - — 


ORIGIN  AND  DEVELOPMENT  OF  INSTINCTS. 


181 


which  it  states  is  a  matter  of  daily  observation.  "  Tricks  of 
manner,"  indeed,  are  of  such  frequent  occurrence  in  the 
nurseiy  and  schoolroom,  that  it  usuaUy  entails  no  small 
labour  on  the  part  of  elders  to  eradicate  them,  and  when  not 
eradicated  m  childhood  they  are  apt  to  continue  throuoh- 
lite,  miless  afterwards  conquered  by  the  efforts  of  the  indi- 
vidual himself.  But  in  cases  where  the  trick  of  manner  isi 
not  obnoxious,  or  sufficiently  unusual  to  call  for  checkin^T  it 
is  allowed  to  persist,  and  thus  it  is  that  almost  every  one 
presents  certain  slight  peculiarities  of  movement  which  we 
recognize  as  characteristic  * 

Such  peculiarities  of  movement  as  we  meet  with  them  in 
ordinary  life  are  slightly  marked ;  but  their  significance  in 
relation  to  instinct  has  been  obtruded  on  my  notice  by 
observing  them  in  the  much  more  striking  form  in  which 
they  are  presented   by  idiots.     This  is  a  class  of  persons 
which,  as  we  shall  find  in  my  next  work,  is  of  peculiar 
interest  m  relation  to  mental  evolution,  because  in  them  we 
have  a  human  mind  arrested  in  its  development  as  well  as 
deflected  in  its  growth— therefore  in  many  cases  supplying  to 
the  comparative  psychologist  very  suggestive  material  "for 
study.     Now  one  of  the  things  which  must  most  strike  any 
one  on  first  visiting  an  idiot  asylum,  is  the  extraordinary 
character  and  variety  of  the  meaningless  tricks  of  manner 
which  are  everywhere  being  displayed  around  him.     These 
tricks,    often    ludicrous,    sometimes    painful,    but    usually 
meaningless,  are  always  individual  and  wonderfully  per- 
sistent.    Generally  speaking,  the  lower  the  idiot  in  the  scale 
ot  idiotcy,  the  more  pronounced  is  this  peculiarity ;  so  that  if 
one  sees  a  patient  moving  to  and  fro  continually,  or  otherwise 
exhibiting  "  rhythmical  movements,"  one  may  be  pretty  sure 
that  the  case  is  a  bad  one.   But  even  among  tlie  hii^her  idiots 
and  "  feeble-minded,"  strange  and  habitual  movements  of  the 
hands,  limbs,  or  features  are  exceedingly  common. 

Among  animals  similar  facts  are  to  be  noticed.     Scarcely 
any  two  sporting  dogs  "point"  in  exactly  the  same  manner, 

,,.•?'•  5*T^?*«'  says  (Mental  PJiysiology,  p.  373),  "  Wliat  particular 
tnck  each  individual  may  learn,  depends  very  much  upon  accident.  Thus, 
in  the  old  times  of  dependent  watch-chains  and  massive  bunches  of  seals 
these  were  the  readiest  playthings,"  &c.  In  view  of  the  relation  which  such 
_  tricks  bear  to  the  formation  of  primary  instincts,  this  remark  has  some 
importance  ;  it  shows  that  even  aimless  movements  may  be  determined  and 
rendered  habitual  by  the  conditions  of  the  environment. 


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182 


MENTAL  EVOLUTION  IN  ANIMALS. 


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me'''fjZ^i^l  ^^^''''  **^  ^''  particular  attitude  through 
when  they  are  threatened,  when  at  plav  &o    ^r,7  rll        ' 

and  indeed  domestic  animals  of  any  kind^mL^l'"" 
noticed  the  diversity  of  their  dispositions  in "esTeTnf  tf^ 
boldness,  amiability,  &c. :  and  Mr  W  T?f^?  ,1^1?^  P^^^' 
large  experience,  if  sure^St  the  d^;S/5^^^^^^^^  ^^^^ 
la^^s^and  canaries  is  displayed  bytSyl'aSrtS 

Almost  innumerable  instances  might  be  given  of  indi 
vidual  variations  m  the  instincts  of  nelt-buildinlf    Event 

conLctnt  MTSrSrMSs'''''  ^^  ''''  ^^^^  "  ^^^-^  to  in  ihi, 

for  many  years  occupied  a  hole  in  a  walWlS  ;'  "S-^^'l"*^  *  P'^^'"  ^^^^^ 
deseribesanother  nest  placedTu  the  sideotll7''1"^u'^-)'  '^"^  ^'•-  ^^^^ 
of  clay  weighing  no  les^s  than  eleven  VonlaJtet.^Z^'  "^  "'*\^.  "'^^^ 
mehes  in  height  (Zoologist,  2nd  ser  r  285nV  T)  1/  "'^•^«"'-i"g  thirteen 
frequently  exhib  ts  variations  in  th^^^rn.f^"        f  goWen-crested  Wren,  also, 

crags  of  rock  ;  but  Mr  D  E  Wv  rJ  /  '^^^  ?''^'''  ''"'^'^^  i°  precipitous 
describes  a  nest  which  he  Welf  if  "^"T  ""  '^l'^^^-'''  1«72,  pp.  141-3)! 
feet  from  the  ground  Coucrsri  th'T'^f'*  "'^  f/^'^''^^'  °°*  ^bove  twenty 
8ometimes  unii  in  occuS  one  nest  anHth  ^°  "^?  ^'^  of  birds  wij 
men,  or  one  of  them  will  surrender  thetnful  %  !f '  *^"^  ^"''"^^  ^°  "om- 
trations  of  Instinct,  p  233)  Mr  S  sJ^^  'l''  ''^  *i'T  ^^^  *^^  «t'^«''  (^^^«*- 
"  From  what  has  be;n  wrSen  ifaDnears  n^« '  7w  ^  '^^  the  Missel-thrush  says, 
plast<.r  in  the  construction  o?'theSSt;ht„^^^^^^ 

which  agrees  with  my  own  leSion  L  ^ff'h'  '"'"^Tt^  ^o  without  it, 
which  did  not  contain  plaster  tKel^^;  rl,  ^^f  °"^^  \  ^"^^  ^"""d  ^^sts 
my  way-and  they  have  bein  not?  few  P^"*  •^^t^^^^^  ^hi^h  have  fallen  in 
Fome  kind  betwee J  tlie  twi^s  and  110^"  t"^'"^^  ^^''^  ^'^^  ^  plastering  of 
invariably  consti'te  th  Zngf  tS^^^e^mnr'"^  *^^  ^'^  f'^''  ""^^'^ 


11 

hi 


OKIGlN  AND   DEVmoPMENT  OF  INSTINCTa.  183 

low  down  in  the  psychological  scale  as  the  insects  we  are  not 
without  evidence  of  individual  variations  of  instinlt  tC, 
for  instance,  Forel  observed  great  diveSt  m  nf  \,.-m-  ' 
among  the  il  <«««W«_the  nZ^b^Sg^'J^Z^eslo^:! 
sometimes  made  under  stones,  and  sometimS  excavaW  t' 

:^  wTitiiet,fnruu'rx''S'iy  tr^^^^^^ 

which  she  holds,  while  another  wIlT  let  them  f^'and^'Z 

.li.w!-'^  shoi^ing  strongly  marked  individual  differences  of 
dispasition  in  animals,  and  also  that  such  differeuMs  mav 
lead  to  useless  or  capricious  actions  having  all  the  stren^h 
a  e  tEt' wh"  h'- '  '""!=  »  g°«i  cl««  of  cies  telfet 

pe7The%t*'f  ■  ""i  '  "'»  -t  it-i^gl  C/i   T. 
pet.     Ihe  bird  soon  became  perfectly  tame   and  then  rnn 
ceived  a  strong,  persistent,  ar/unremitting  atLchment  to  a 
peacock  which  also  belonged  to  the  establisliment  WW^^^^^^ 

wasnoTTnr  '11"^?'^  ^emarkable^rom  the  fact  that  k 
was  not  m  the  smallest  degree  reciprocated  by  the  peacock 

?or  Tnred'td'bV'^'^'t  '^^'-^^  ^^«  constant  Zp  it 
behind  hi'm  t  -  f.T  *°  ^^^'""  ^^'^^  «^«  ^^^  always  just 
CO  tai  ?hp  tn  "  ^''  ""''^^J"  ^"°«^  ^P°"  the  gable  of  a 
and  e^ven  I^Jf     widgeon  could  not  fly  to  accompany  him; 

aiu  upon  me  gable;  but  she  always  kept  as  near  him  a^  oiv 
cumstances  wou  d  permit,  for  as  soon  as  he  flewTp  to  h  s" 
gable  she  would  squat  herself  down  upon  the  groTnd  just 

:t7£bt\*r^CtftS^^^^^^^^  be  multiplied  indefinitely.,  but  a, 
Mr.  Darwin's  essay  at  the  end  of  ?2  shook  it  L'''"-;^?^  T''  ^'^  g'^«°  i° 
anj  further  illustrations  °  '  '*  '^  ''^^^^^'^^  ^"^  ""^  to  adduce 


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184 


MENTAL  EVOLUTION  IN  ANIMALS. 


i   '-Hi 


iky 

L  Jiil;..,    .   ^ 

!l  .T  '^n  ^^^°t^o"  ^Iiich  eventually  cost  her  her  life  as 
she  thus  feU  a  prey  to  a  prowling  cat/  Now  here  we  have^ 
curious  case  of  a  bird  that  had%een  wild,  takiL  a  ylZnt 
fancy  for  the  wholly  useless  companionship  of  afothS  and 
very  dissimilar  bird;  for  it  should  be  added  that  shechose 
the  peacock  as  the  object  of  her  persistent  regard  out  of  a 

isrp^r  ^'^^'  ^'^  ^^  ''--'"^  birds  whicrii;'ed^ 

Similarly,  cats  often  like  to  associate  with  horses  and  in 
some  cases  with  dogs,  birds,  rats,  and  other  unliLwea^^^^^^^^ 
Dogs  not  unfrequently  make  friendships  with  a  vSfetv  of 
animals,  and  in  a  case  recorded  by  F.  Cuvier  a  terrier  fnLr5 
80  much  delight  in  the  companionship  of  a  ca-e^^^^^^ 
when   the  lion  died  the  dog  pined  away  and  died  also 

trprr'^f^'iT^'  ?'^'  ^°  ^^^^^  ^°^«««  ^^^^  become  C* 
tremely  attached  to  dogs  and  to  cats,  and  seemed  pleased  to 
have  them  placed  on  their  backs  in  their  staUs."*  Een-er 
mentions  a  monkey  which  was  so  fond  of  a  dog  that  it  cried 
with  grief  during  the  absence  of  its  friend,  carSssed  it  on  Tts 

'iTp^r-'^l''^^  ''  ^^^^^  ^''  quarrels'with  ol  r  doS 
A  peccari  m  the  menagerie  at  Paris  formed  a  stron-  attach- 
ment with  one  of  the  keeper's  dogs,  and  a  seal  in  the  ame 
place  allowed  a  little  water-dog  tS  play  with  it  Tnd  to  take 
fft  Ta  'u  !?°"*\  which  it  always  resented  if  this  were 
attempted  by  the  other  seals  in  the  same  tank.  Do4  have 
lived  on  terms  of  friendship  with  guUs  and  ravens      " 

waLV'&c   Icr""  ^''''^''  ^°  accompany  his  master  in  his 
Colonel  Montagu,  in  the  Supplement  to  his  "Ornitho- 
logical Dictionary,"  p.  165,  relates  the  following  Sular 
instance  of  an  attachment  which  took  place   between    a 

Srd    anf  r^'t  '  P"'^^?    "  ^^^  ^"»  ^^d  ^^^^^  the  male 
bud,  and   had  been  most  severely  punished  for  the  mis- 

fm  tl  1  .?^  ''^'^^'^  ^'''''^  ^'^^^^  extremely  distressed 
for  the  loss  of  her  partner  and  only  companion ;  and  probably 
having  been  attracted  to  the  dog's  kennel  by  the  sight  of  her 
dead  mate,  she  seemed  determin^ed  to  persecute  the  dog  by 

«^Ir'«T.fTV^"'''^f^''/^^  "°"t^^"^l  vociferations;  but 
after  a  little  time  a  strict  friendship  took  place  between  these 
incongruous  animals.    They  fed  out  of  the  same  trough,  lived 

•  Thompson,  Passions  of  Animals,  pp.  360-1.  f  Ibid. 


't'l,' 


ORIGIN  AND  DEVELOPMENT  OF  INSTINCTSp 


185 


under  the  same  roof,  and  in  the  same  straw  bed  kept  each 
other  warm ;  and  when  the  dog  was  taken  to  the  field,  the 
lamentations  of  the  goose  were  incessant," 

The  same  author  gives  ases  of  attachment  between  a 
pigeon  and  a  fowl,  a  terrier  and  a  hedgehog,  a  horse  and  a 
pig,  a  horse  and  a  hen,  a  cat  and  a  mouse,  a  fox  and  harriers, 
an  alligator  and  a  cat,  &c.,  all  as  having  fallen  under  his  own 
observation.     {Ihid.y  p.  162.) 

It  is  not  impossible  that  the  so-called  "  domestic  pets " 
which  are  kept  by  many  species  of  ants*  may  really  be  use- 
less adjuncts  to  the  hive,  capricious  love  of  association  having 
perhaps  in  these  ants  become  by  inherited  habit  truly 
instinctive.  This,  at  any  rate,  must  be  the  explanation  of  the 
fact  that  birds  of  different  species  will,  even  in  a  state  of 
nature,  occasionally  associate,  as  is  the  case  with  Guinea- 
fowls  and  partridges,  and,  according  to  Yarrell,  with  par- 
tridges and  landrails.  Such  unusual  cases  among  birds  in  a 
state  of  nature  are  of  special  interest,  because  they  may  then 
properly  be  regarded  as  the  beginnings  of  such  a  firmly  set 
and  truly  instinctive  association  as  that  which  obtains 
between  rooks  and  starlings,  &c.t 


;•!# 


Enough  has  now  been  said  in  support  of  Proposition  I, 
viz.,  that  non-intelligent  habits  of  a  non-adaptive  character 
occur  in  individuals.  We  shall  next  proceed  to  Proposition  II, 
viz.,  that  such  habits  may  be  inherited. 

That  this  is  the  case  with  tricks  of  manner  in  man  is  a 
matter  to  be  observed  in  almost  every  family,  and  was  long 
ago  pointed  out  by  John  Hunter.  Mr.  Darwin  in  his  MSS 
gives  a  case  which  he  himself  observed,  "  and  can  vouch  for 
its  perfect  accuracy."  "  A  child  who  as  early  as  between  her 
fourth  and  fifth  year,  when  her  imagination  was  pleasantly 
excited,  and  at  no  other  time,  had  a  most  peculiar  trick  of 
rapidly  moving  her  fingers  laterally  with  her  hands  placed 
on  the  side  of  her  face ;  and  her  father  had  precisely  the 

•  See  Animal  Intelligence,  pp.  83-4. 

t  Prof.  Newton,  F.R.S.,  informs  me  that  "bands  of  the  Golden-crested 
Wren  may  frequently  be  observed  in  winter  consorting  with  bands  of  the 
Coal-Titmouse,  and  in  a  less  degree  with  those  of  the  Long-tailed  Titmouse ; 
while  parties  of  Redpoles  and  Siskins  will  for  a  time  join  their  company,  or  vice 
versa.  The  flocking  together  of  Rooks  and  Daws  is,  of  course,  an  everyday 
occurrence,  as  is  also  for  some  months  the  association  of  Starlings  with  them, 
and  in  umny  cases  the  combination  of  all  with  Lapwings. 


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MEXTAL  EVOLUTION  IN  ANIMALS. 


n'hrr'^^^^-  instance  there 

man;efwth"a?:mrnSL'h^  P^^^^^^^^  ^"«ks  of 

seen;  her  puppy' wl^^h  neveVouH  h«^  ""^''^  ^^  ^'^  ''^' 
beg,  now  when  f  lU  grow^SoTm.  .i.^«^^^  ''""  ^""  ^^^^^r 
ment  exactly  in  the ''same  w^ay  "f  '''^'  ^''''"''  ^°^'- 

differences  of  thirS  nfnvl  °'-*^  ''"  ^°^  "^^rked 

different  breeds     Itlni  hf    ''''T  '^-"''^^^y  distinctive  of 

are  only  concerned  She  X'>  ^'^^^^  ''  ^'''''''  ^« 
gent,  or  non-adrptivThabits  and  H  ?  ^^  "^eless,  unintelli- 
to  do  with  the  iisefS  andii  ^^^^^^"  ^^'^  nothing 
into  our  various'^ces  otlgf  fc^„3^,ttr^^^  are  bred 
combined  with  training    \„7  °^^^"?  ^^^/^^ificial  select  on 

meaningless  traits  of  "htractefw^^^^^^  ?r  '^'  ''''  '^  ^^^^^^ 
the  animals  themselvpcrnr  ff  '  ^^®  ""^  ^°  "««  either  to 

heredity  at  woT  Thus  for  ."n'^f"'  ^'  ^"^  ^^^  ^^A^^^ces  of 
annoying  habifof  ba  kin'  round"'"'  '^'  "'^^^^'^  ^^^  ^^«^ 
among  sundry  breedVnf  ?i^  ^  ^  carnage,  which  occurs 
the  coUie,  anJ  is  t^uiylnZ' ''  ^ff^^^^^Y  pronounced  In 
This  is  shown  by  the  ta  tw'^^  T  ^T^.^^^°^  «^  ^^^i^^tion. 
W  never  seenCthertof  ^^^^^^^^  '^^  P™^^°°^ 

spontaneously  begin  to  do  so-?  V   ^^""f^^"^'^  nevertheless 

of  character  o^rdisposilnpeeuliano'^^^^  '''^'''.  '''''' 

-ntioned;  butlLnpasr^nt^^o^rrm^^^^^^^^^^ 

^^*;^'^^^^^^^^  -'«^  -  '---^^  o/^„,.„^  ,„, 

perfomteTo^Slie'nraT^^^^  s^JlZT?"^  ^^^^"'l  Syke  terriers 
to  somerace-distiuction  of  a  psychl5'J,\  if  ^^'  ^°''°°  ''^"^^  *»  be  due 
vidual  peculiarity.  It  thereJe  leads  on  t  .1?  '  f  "**  ?°'  "^^'^'^  *«  "^n  iudi. 
in  the  text.  ^^""^^  o°  to  the  class  of  cases  uekt  considered 

J  See  Mature,  toI.  xix,  p,  234. 


ORIGIN  AND  DEVELOPMENT  OP  INSTINCTS.  187 

I  have  met  with  in  dogs  of  the  inheritance  of  a  thoroufflily  sense- 
less psychological  pecuharity.     I  refer  to  the  instance  which 
was  comniunicated  some  years  ago  to  Mr.  Darwin  by  Dr. 
Huggins.  IRS.,  and  which  I  shall  quote  in  his  own  words 
{nT,.r.LT'       ?  communicate  to  you  a  curious  case  of  an 
inherited  mental  peculiarity.     I  possess  an  English  mastiff 
by  name  Kepler  a  son  of  the  celebrated  Turk  out  of  Venus.' 
1  brought  the  dog,  when  six  weeks  old,  from  the  stable  in 
winch  he  was  born     The  first  time  I  took  him  out  he  started 
back  in  alarm  at  the  first  butcher's  shop  he  had  ever  seen 
1  soon  found  he  had  a  violent  antipathy  to  butchers  and 
butchers'  shops.    When  six  months  old  a^ervant  took  him 
with  her  on  an  errand.    At  a  short  distance  before  coming  to 
the  house  she  had  to  pass  a  butcher's  shop ;  the  dog  threw 
himself  down  (being  led  with  a  string),  neither  coaxin"  oT 
threats  would  make  him  pass  the  shop.     The  dog  was  too 
heavy  to  be  carried  and  as  a  crowd  collected,  the  servant  had 
to  return  with  the  dog  more  than  a  mile,  and  then  go  without 
.i-m'.i  "'  ^^^"^fl  about  two  years  ago.     The  antipathy 
still  continues,  but  the  dog  will  pass  nearer  to  a  shop  than 

on  ZT^  TTm  ^-^  u  ^'^^  ^^'^  "^^^^^^  ^SO,  in  a  little  book 
on  dogs,  published  by  Dean,  I  discovered  that  the  same 
strange  antipathy  is  shown  by  the  father.  Turk  I  then 
v^rote  to  Mr.  Nicholls,  the  former  owner  of  Turk  to  ask  tm 
tor  any  information  he  might  have  on  the  point.    He  replied 

ofTnvv'?^T  v  'r"\^"^^P^^^^^^^^«^«  ^^  King,  the  sire 
of  Turk,  in  Turk,  in  Punch   son  of  Turk  out  of  MeS),  and  in 

Pans  (son  of  Turk  out  of  Juno).     Paris  has  the  greatest 

an  ipathy,   as  he  would  hardly  'go  into  a  street  where  a 

butchers  shop  ls.  and  would  lun  away  after  passinc.  it 

When  a  cart  with  a  butcher's  man  came  into  the  place  where 

the  dogs  were  kept  although  they  could  not  see  him,  they 

all  were  ready  to  break  their  chains.     A  master-butcher 

tiTZJ'Tih'f'i  °"'  '^'^^"S  on  Paris'  master  to  see 
the  dog.  He  had  hardly  entered  the  house  before  the  do- 
(though  shut  in)  was  so  much  excited  that  he  had  to  be  put 
into  a  shed,  and  the  butcher  was  forced  to  leave  without 
seeing  the  dog  The  same  dog  at  Hastings  made  a  spring  at 
a  gentleman  who  came  into  the  hotel.  The  owner  caught  the 
dog  and  apologised,  and  said  he  never  knew  him  to  do  so 
betore,  except  when  a  butcher  came  to  his  house  The 
gentleman  at  once  said  that  was  his  business ' " 


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188 


MENTAL  EVOLUTION  IN  ANIMALS. 


We  see,  then,  tliat  non-intellirrent  habits  of  non-nrlnnf iv« 

anim^rAfr""  r^'.^  «tro'ngly  inherited  b7  dots 
animals   As  showing  tlmt  the  same  is  true  of  breeds  or  strain. 

strong  „„e„stral  instinct,  is  one  which  is  communicated  to 
Mr  IJarwm  ma  letter  from  Mr.  Thwaits,  who  S  from 
mTX^^Vmss''  T'  7^  -'-'' '-^'ter  I  iiXm^^ 

^"Si"li^?  '--- »™™'  i^XSii'fei 

todTwhl^tSbrplaceTt  :tb  or °;  '^''^  ^™"« 
alarmed"  and  have  i  t";'ickVtatV Ln^L'-^o  fi 
v^^ould  drown  in  their  struir-'liuf^"  Mr  ThJolf.  aa  \\,Z 
this  pecdiarity  does  not  IS  to  eSi  Ihe  tcto  la  the 
island,  but  only  occurs  in  one  particular  breed  or  strain 

In  Mr.  parw,„'s  MSS  I  also  iind  the  folIowiL  remarks  • 
difeent^JrtsTM™'  ""^-^h^ve  stated  that  Wsef  a 

trtl'e'' ;';r  r""»'  P^™^  have  bjracti  e'd  S 
^bLr'vSLlh^  \r?rhe"ittdT'  ^■"   ^"1^  "'»"  " 

?:;drs$-SE«h^i^:sSSS 

•  personal  Narrative,  vol.  iii,  p.  383. 

Btruck  by  no  horse  on  the  grL  y  P  S'^  LaX'*'^  *^'\u^  """^  ^""""^l^ 
action  of  some  English  horses  ''  For  1  nn  v>  J"  ^V"-  ^^"^  "'^t"™!  ^'igh 
ditar,  transmission^f  qual  t ts  in  the  ca  a^nf  H  ^  t^''  '"'*"""«^  "^  '^^^• 
^nma/«  a«d  Plants.  &l.  vo  ?  pp  iVg  "'"'  ''^  ^'"•*«''o»  «/ 


OUIGIN  AND  DEVELOPMENT  OP  INSTINCTS. 


189 


■'M 


ancient  times  in  the  East,  when  flying  pigeons  was  much 
esteemed.     Tumblers  have  the  habit  of  flying  in  a  close 
flock  to  a  great  height,  and  as  they  rise  tum'bling  hoad  over 
tail.     I  have  bred  and  flown  young  birds,  which  could  not 
possibly  have  ever  seen  a   tumbler;  after  a  few  attempts 
even  they  tumbled  in  the  air.     Imitation,  however,  aids  the 
instinct,  for  all  fanciers  are  agreed  that  it  is  highly  desirable 
to   fly   young   birds   with   firat-rato   old   ones.     Still   more 
remarkable  are  the  habits  of  the  Indian  sub-breed  of  tumblers, 
on  which  I  have  given  details  in  a  former  chapter,  showing 
that  during  at  least  the  last  250  years  these  birds  have  been 
known  to  tumble  on  the  ground,  after  being  slightly  shaken, 
and  to  continue  tumbling  until  taken  up  and  blown  upon. 
As  this  breed  has  gone  on  so  long,  the  habit  can  hardly  be 
called  a  disease.     I  need  scarcely  remark  that  it  would  be  as 
impossible  to  teach  one  kind  of  pigeon  to  tumble  as  to  uMch 
another  kind  to  inflate  its  crop  to  the  enormous  size  which 
the  pouter  pigeon  habitually  does."* 

This  case  of  the  tumblers  and  pouters  is  singularly 
interesting  and  very  apposite  to  the  proposition  befove"us,  for 
not  only  are  the  actions  utterly  useless  to  the  animals  them- 
selves, but  they  have  now  become  so  ingrained  into  their 
psychology  as  to  have  become  severally  distinctive  of  different 
breeds,  and  so  not  distinguishable  from  true  instincts.  This 
extension  of  an  hereditary  and  useless  habit  into  a  distinction 
of  race  or  type  is  most  important  in  the  present  connection. 
If  these  cases  stood  alone  they  would  be  enough  to  show  that 
useless  habits  may  become  hereditary,  and  this  to  an  extent 
which  renders  them  indistinguishable  from  true  instincts.f 

In  the  Appendix  several  instructive  cases  of  the  same 
kind  will  be  found,  such  as  that  of  the  Abyssinian  pigeon, 
which,  when  fired  at,  "  plunges  down  so  as  almost  to  touch 
the  sportsman,  and  then  mounts  to  an  immoderate  height  ;"J 
the  biscacha,  which  "  almost  invariably  collects  all  sorts  of 

*  For  further  particulars  on  the  instinct  of  tumbling,  see  Variation  of 
Am  mail  and  Plants,  vol.  i,  p.  219,  and  230. 

T  Some  years  ago  the  Ratels  wliicb  were  confined  in  one  cage  at  the 
Zoological  Gardens  acquired  the  apparently  useless  habit  of  perpetually 
tumbling  head  over  heels.  If  their  progeny  were  to  be  exposed  for  a  number 
of  generations  to  similar  contiitions  of  life,  they  would  probably  develope  a 
true  instinct  of  turning  somersaults  analogous  to  that  of  the  tumbler- 
pigeon. 

I  I  have  frequently  noticed  a  similar  propensity  in  the  Lapwing. 
13 


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190 


MENTAL  EVOLUTION  IN  ANIMALS. 


'',.    Ill 


,  I 


i!'|i  ! 


?he  same  spot  to  S "p    h  ir  eteleTt"-°h"f  *'*!,'"'^''  '? 

thus  beco™  .cial  ohreSLror^S^Ll-L^Si^d 

Passing  on,  thp.n,  to  Propositions  HI  and  TV     v,V    /;  * 
mch  habits  may  vary  and  that  ,,,7,.  J  A  y»— viz.,  that 

obliteratedlLTVL  iT  ^^^/^^^^^^o^  of  becoming 
manv  true  instScN  kl  S'L  P'^'^i-^^  '""'  ''  ^^^  ^ase  with 
specUZZonkl  onmZ'nf  ^f^f'^'^^  ^^  the  same 
aLestral  disposition  must  Wv^^^^^^  '^''   the 

have  then  continued  to  be  inherited^nl.r  ^^.%PT^«"y.  ^^d 
the  several  lines  of  descendants  ''  '^^'^^ 

eas/Hntmrnyri^^^^^^^  -  not 

habits,  nor  is  itfmporSS  that  f  ^  ?7^  °^  ^^^^^^^ 
illustrations  on  this  head     ThL  ,•    T^"^/'"^"  ^  """^^^^  ^^^ 


ORIGIN  AND  DEVELOPMENT  OF  INSTINCTS.  191 

as  to  become  accidentally  beneficial  to  the  animal  then  we 
are  bound  to  believe  that  natural  selection  would  fix  this 
habit,  or  Its  beneficial  variations.  And  the  proof  that  such 
.  a  process  has  caken  place  is  given  by  the  fact  of  Zivh^Ta 
many  instincts -such  as  the  incubating  instinct  beforf 
alluded  to-which  cannot  conceivably  have  been  developed 

I'kT^?^?  .T^:.  ^^^^^^^^  ''  ^°<^^his  instinct  be^rin 
habits  adapted  to  the  protection  of  the  eggs  it  h  certain  th«f 

tTZ^  ''''/?""  ^''^  ^^"  intelligentrUrLet^^^^^^^^ 
ing  them ;  and  it  is  no  less  certain  that  before  the  instinct 
attamed  its  present  degree  of  perfection,  it  must  have  passed 
through  many  stages  of  variation,  few    f  any  of  which  can 
have  been  due  to  intelligent  purpose  on  the  part  of  the  birds 
And  further  proof  is  rendered,  as  I  have  also  previouslv 
observed  by  the  fact  that  many  instincts  are  displard  by 
animals  too  low  m  the  zoological  scale  to  admit  of  our  sup^ 
posing  hat  they  can  ever  have  been  due  to  intelligence     To 
give  only  one  illustration,  the  larva  of  the  caddice  fly Xes  in 
water  and  constructs  for  itself  a  tubular  case  made  of  virtus 
particles  glued  together.    If  during  its  construction  tWsJase 
IS  found  to  be  getting  too  heavy_ie.,  its  specific  aravitv 
greater  than  that  of  the  water-a  piece  of  leaf  or  strawls 
selected  from  the  bottom  of  the  stream  to  be  added  to  the 
structure ;  and  conversely,  if  the  latter  is  found  to  be  aettina 
too  ight,  so  as  to  show  a  tendency  to  float,  a  small  stone  "f 
morticed  m  to  serve  as  ballast.*    In  such  a  castas  thit    f 
seems  impossible  that  an  animal  so  iow  in  the^oolo^  ca 
scale  can  ever  have  consciously  reasoned-even  in  the  most 
concrete  way--that  some  particles  have  a  hii  sperfic 

tCL^Y^  ''^%''  '^^  '^''  ^y  '^^^S  a  particle  of  tC  o 

that  substance,  the  specific  gravity  of  the  whole  struoh,rJ 

may  be  ac'justed  to  that  of%he  Lter.     Yet  the  act  ons 

involved  are  no  less  clearly  something  more  than  reflex    thev 

are  instinctive,  and  can  only  have  been  evolved  by  natuS 

selection.     SimUarly,  Professor  Duncan  suSs  in  a  lecture 

before  the  British  Association,  1872,  that  the  ns  Let  of  the 

Odynerus- whichfoms  a  tubular  ante-chamber  and  provision! 

wH^hTt  f:^  ""''^  «t^^g  g'-ubs  for  the  future  use  ofTfflp  ring 

which  It  never  saw-probably  arose  in  this  way.     M  Fabrl 

has  oDserved  that  Bemlex  indica  lays  an  egg  in  afhamber 


I 


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I.U. 

I     ■:  J.  1 


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192 


MENTAL  EVOLUTION  IN  ANIMALS. 


Ill 


lib 


and  that  the  egg  hatches  very  shortly.  The  insect  then  visits 
Its  living  offspring  every  day,  bringing  it  small  larvae  stung 
to  keep  them  qniet.  Now  this  instinct  may  have  been 
altered  m  Odynerus  by  a  delay  arising  in  the  time  of  hatch- 
ing, and  a  series  of  victims  having  been  therefore  placed  in 
the  provision-chamber  in  obedience  to  the  primitive  instinct 
wliich  has  thus  become  modified  into  a  n«w  one.  ' 

^  Numerous  other  instincts  will  be  found  mentioned  in  the 
Appendix,  the  origin  of  which  can  only  be  attributed  to  the 
uncompounded  influence  of  natural  selection.  I  feel  there- 
fore, that  It  IS  needless  for  me  to  adduce  further  illustrations 
and  so  shall  here  conclude  my  observations  on  instincts  of 
the  primary  class. 

Secondary  Instincts. 

c  ^Sw".?  ^°^  ^^?^^  ^^'^^^^  ^^"^s  of  propositions,  we  shall 
find  that  their  proof  casts  a  good  deal  of  reflected  light  upon 
those  which  we  have  just  considered— light  which  tends  still 
further  to  demonstrate  the  latter. 

First,  then  we  have  to  show  that  "intelligent  adjustments, 
when  frequently  performed  hy  the  individual,  become  automatic 
either  to  the  extent  of  not  requinng  conscious  thought  at  all  or 
as  consciously  adjustive  haUts,  not  requiring  the  same  deqree  of 
conscious  effort  as  at  first.  *' 

The  latter  part  of  this  proposition  has  already  been 
proved  m  an  earlier  chapter  of  this  book.    That  "  practice 
makes  perfect     is  a  matter,  as  I  have  previously  said  of 
daily  observation.     Whether  we  regard  a  juggler,  a  pianist, 
or  a  bilhard  player,  a  child  learning  his  lesson,  or  an  actor  his 
part  by  frequently  repeating  it,  or  any  one  of  a  thousand  other 
Illustrations  oi  the  same  process,  we  see  at  once  that  there  is 
truth  m  the  cynical  definition  of  a  man  as  "  a  bundle  of 
habits.       And  the  same,  of   course,  is  true  of   animals. 
Iraining      an  animal  is  essentiaUy  the  same  process  as 
educating  a  cnild,  and,  as  we  shall  presently  have  occasion  to 
show,  animals  in  a  state  of  nature  develop  special  habits  in 
relation  to  local  needs. 

The  extent  to  which  habit  or  repetition  may  thus  serve 
to  supersede  conscious  effort  is  a  favourite  theme  amor  y 
psychologists ;  and  one  or  two  instances  have  already  been 
given  in  the  chapter  on  the  Physical  Basis  of  Mind.  To 
this  point,  therefore,  I  need  not  recur. 


ORIGIN  AND  DEVELOPMENT  OP  INSTINCTa  193 

aasooiat^d  with  tZ^L^'^Zi^'Z:^::^  ^^h"? 
as  Professor  Alison  remarks  *  the  sensp  nf Tn^S,;    •  ■'■ 

mtin^^Ln    .'^''tr"'?  ."""^'-g^'^haWe  from  a   true 

the  js  of  „?;l'cs  ^hr'^rs  u-L*; 

SotSrnelhEoTpa.^r'""  "''''"''  '^^. 

Accepting,  then,  Proposition  VI  as  beyond  dismifp  ^. 
have  here  to  substantiate  Proposition  VII  vff  r  J/S  '  -^ 
«c^^o^  an^  con.c^•o^..  habits  lay  he  Iheriied    '        '  '''*''^"'^' 

Now  we  have  already  seen  that  this  is  certainly  the  case 

!  t^'^^  "Instinct,"  Todd's  Cy do.  of  Anat    vol  iii  Ifiqq 

observed  in  animals  ^d  the  MS  Ivl'"*'-  J'"V'«"-reIation  is  also  to  be 
an  idiotic  dog.  whos'e^nstinct  Slf  ^  case  which  Mr.  Darwin  observed  of 
probably,  ofVeTsVnT"o??ormw"f  Sln' Ion" '^"^'°'^°  ^^^^'"'•^"*' 
developed  or  so  little  checked  by  intelligence  "  tffhf  hS  jT""  '°  '^''^^^^^ 
turn  round  twenty  times  before  lying  down ''  ^^'°  """""^^'^  *« 

of  a  sl'n1ar7i^sSr^rw  Irr"**'':'^ '^  '^^^'''^^'J  ^«  tl'^  -rvival 
from  intelligent^.  ri^SthroZTaH  It '?-*'°'^^^  are  formed  by  a  descent 

fore  it  is  interesting  th^t  when  a^^ 

as  instincts,  they  arc  found  to  resemhT«  n^.f       ?  "»«;<;hey  ^re  fully  formed 

um.estrictedplay^henTteufinrS'eirbS^d^rS^^^  "  ^^*^-"g  -"' 


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194 


MENTAL  EVOLUTION  IN  ANIMALS. 


fj    . 


With  automatic  actions  which  have  arisen  accidentally,  or 
without  intelligent  purpose;  and  it  would  be  anomalous  were 
the  fact  otherwise  with  automatic  actions  which  have  been 
acquired  consciously.  The  evidence  that  the  fact  is  not 
otherwise  is  considerable. 

Pn  Jint""^  ""F  ^^^'^  *^^  '^'^  °^  "^^"-     "  On  what  a  curious 
combination  of  corporeal  structure,  mental   character,  and 
tiaining,    says  Mr    Darwin,  "must  hand-writing  depend! 
Yet  every  one  must  have  noted  the  occasional  close  similarity 
of  the  hand-writing  in  father  and  son,  although  the  father 
had  not  taught  the  son    ....     Hofacker^ in  Germany, 
remarks  on  the  inheritance  of  hand -writing ;  and  it  has  been 
even  asserted  that  English  boys,  when  tSught  to  write    n 
France.  naturaUy  cling  to  their  English  manner  of  writing" 
Dr.  Carpenter  says  he  is  "assured  by  Miss  Cobbe  that  in  her 
family  a  very  characteristic  type  of  hand-writing  is  traceable 
through  >e  generations;"    and  in  his  own  "family  there 
occurred  a   curious  case  of  a  gentleman  who  inherited  a 
constitutional    character  of  hand-writing,  and  lost  his  richt 
arm  by  an  accident;    "in  the  course  of  a  few  months  he 
learnt  to  write  with  his  left  hand,  and  before  long  the  hand- 
wnting  of  the  letters  thus  written  came  to  be  indistinguish- 
able from  that  of  his  former  letters."     This  case  remSr^e 
of  a  fact  which  I  have  frequently  observed-and  which  has 
doubtless  been  observed  by  others-viz.,  that  if  I  write  in  any 
unusual  direction   as  for  instance,  on  the  perpendicular  face 
of  a  recording  cylinder),  the  hand-writing  is  unaltered  in 
character,  although  both  the  hand  and  the  eye  are  working  i^ 

^31^'''^^°'^"?'  '"^  '*'^"g  ^«  ^h«  mm^a^  element  in 
hand-writing.     Similarly,  as  observed  in  a  previous  chapter 

f  one  takes  a  pencU  m  each  hand  and  writes  the  same  word 
Z^hi  ,fi  I  '  simu  taneously-the  left  hand  writing  from 
right  to  left--on  holding  the  backward  written  word  before 
a  mirror,  the  hand- writing  may  at  once  be  recognized 

Many  other  instances  might  be  given  of  the  force  of 
inheritance  m  the  mental  acquisitions  of  man.*    But  turning 

Idves  t^e^7T^Jhf:^*''\^J^^ff^y'  PP.-  39^-4'  "'^'^^  h«  discusses  and 
pves  caaes  ot  hereditary  aptitude  for  music  and  painting.     Also  Galfon'« 

tfnt   '^  ©^"^f*.  for  high  mental  qualities  running  in  fammes    eithe!  in 
the  same  or  m  analogous  lines  of  activity ;  and  Spencer  (PsSo2  i  p  S 
or  «  E?"  in'f  ™''"^. -^  psychology  in  Lm.    Th^e  eifect.  o/''  goK^edit  /•      • 
or    blood    in  bequeathing  hereditary  disposition  and  refinement  have  aSy 


ORIGIN  AND  DEVELOPMENT  OF  INSTINCTS. 


196 


m 


now  to  the  more  important  case  of  animals,  I  shall  give  only 
a  few  examples  among  almost  any  number  that  I  could 
quote.  Thus,  in  Norway,  the  ponies  are  used  without 
bridles,  and  are  tramed  to  obey  the  voice ;  as  a  consequence 
a  race-pecuharity  has  been  established,  for  Andrew  Knight 
says  "the  horse  breakers  complain,  and  certainly  with  very 
good  reason,  that  it  is  impossible  to  give  them  what  is  called 
a  mouth;  they  are  nevertheless  exceedingly  docile,  and  more 
than  ordmarily  obedient,  when  they  understand  tlie  commands 
of  their  masters."*  Again,  Mr.  Lawson  Tait  tells  me  that  he 
had  a  cat  which  was  taught  to  beg  for  food  like  a  terrier,  so 
that  she  developed  the  habit  of  assuming  this  posture— so 
very  unusual  in  a  cat— whenever  she  desired  to  be  fed.  All 
her  kittens  adopted  the  same  habit  under  circumstances  which 
precluded  the  possibility  of  imitation ;  for  they  were  oiven 
away  to  friends  very  early  in  life,  and  greatly  surprised^theip 
new  owners  when,  several  weeks  afterwards,  they  began 
spontaneously  to  beg.f 

In  order  to  show  that  the   same  principles  apply  to 
animals  m  a  state  of  nature,  it  will  be  enough  to  adduce  the 
one  instance  of  hereditary  wildness  and  tameness,  for  this 
instance  affords  evidence  of  the  most  conclusive  kind.    Wild- 
ness or  tameness  simply  means  a  certain  group  of  ideas  or 
disposition,  having  the  character  of  an  instinct,  so  that  we 
may  properly  speak  of  a  wild  animal  as  "  instinctively  afraid  " 
of  man  or  other  enemy,  and  of  a  tame  one  as  instinctively 
the  reverse.     Indeed,  one  of  the  most  typical  and  remarkable 
illustrations  of  instinct  that  could  be  given  is  that  of  the  in- 
born dread  of  enemies,  as  exhibited,  for  instance,  by  chickens 
at  the  sight  of  a  hawk,  by  horses  at  the  smell  of  a  wolf,  by 
monkeys  at  the  appearance  of  a  snake,  &c.    Now,  fortunately 
there  is  material  for  amply  proving  both  that  these  instincts 
may  be  lost  by  disuse,  and,  conversely,  that  they  may  be 
acquired  as  instincts    by  the    hereditary  transmission    of 
ancestral  experience. 

been  alluded  to,  and  I  think  observation  will  show  that  the  same  applies  to 
the  sense  of  modesty.  i-f  ™  w 

•  FAil.  Trans.,  1839,  p.  369. 

t  Inasmuch  as  thp  action  of  "begging"  is  so  unusual  in  the  Cat,  the 
above  case  of  its  he  p  -.tsvy  transmission  is  more  remarkable  than  the  similar 
cases  which  occur  i-  u  Dog  ;  see  Lewes,  Problems  of  Life  and  Mind.  vol.  i, 
p.  JJ9,  and  i  lake  Cosmic  Philosophy,  vol.  ii,  p.  150,  and  mo  e  especiallv  a 
case  recorded  by  Mr.  L.  Hurt,  in  Nature  (Aug.  1,  1872)   of  a  Skye  ter/iei 


i| 


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196 


MENTAL  EVOLUTION  IN  ANIMAL8. 


>  I   I 


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m.J^  r?l*^f*  instinctive  wildness  natural  to  a  species 
ra/biL'     1?L'^T  '^  ^^"'^-^"ly  rendered  by  the  cLe  o 
rabbits      As  Mr.  Darwin  remarks,  "hardly  any  animal  is 
more  difficult  to  tame  than  the  young  of  the  wild  rabbit 

raTbit'^uTl'rb  %  '^""  '""k  ^^^  y-»«  of  ?he  tame 
rabbit    but  I  can  hardly  suppose  that  domestic  rabbits  have 

at  le^astXtf;^  for  tameness  alone  ;  so  we  must  attribule 
at  least  the  greater  part  of  the  inherited  change  from  extreme 
wildness  to  extreme  tameness,  to  habit  and'long-cont  S 

tZaTnNTV  '"'  '"  ^^^  ^^^  ^«  ^dd«'  "Captain 
buhvau,  KN.,  took  some  young  rabbits  from  the  Falkland 

Islands,  where  this   animal  has   been  wild  (i.e.    feral)  for 

several  generations,  and  he  .'s  convinced  that  they  are  more 

Zul  'Tk^  '?'^  ''^\  ^^^  ^^^bi^«  in  Engla^nd  The 
facility  of  breaking  m  the  feral  horses  in  La  Plata  can  I 
think,  be  accounted  for  on  the  same  principle  of  some  Httle 

W "  Ziull'Z'T''^  being^ong^nhereTinll! 
breed.  Similarly  Mr.  Darwin  points  out  in  his  MSS  that 
there  is  a  great  contrast  between  the  natural  tameness  of  the 
tame  duck  and  the  natural  wildness  of  the  wild.t  The  still 
more  remarkable  contrasts  which  are  presented  between  our 
domestic  dogs,  cats  and  cattle  I  shall  consider  later  on :  for 
m  them  it  is  probable  that  the  principle  of  selection  has 

belonging  to  him  which  had  great  difficulty  in  acquirinff  bv  tuiHon   fl, 
accomphshment  of  begging,  but  afterwards  habituairpSed  it  as  a  S^n.™! 
expression  of  desire.     Mr.  Hurt  then  adds    "  OnT-.f  i?™'^"^®^  "  as  a  general 
never  ,ee„  her  f«U.„,  i.  i„  ZV.ZAit  of  .it.  „s'L^'£l™i'i°  J" 

Ihe  wild  rabbit,'  says  Sir  J.  Sebright  (On  Instincts  1836  n  inw;«  k 
far  the  most  untameable  animal  that  I  know   „nH  t  i         i    i  P'    "^    "  ^^ 
British  Mammalia  in  mv  possession     T  S^V  T     .i,^''''^  ''''**  °'°'*  °*  ^^^^ 
nest,  and  endeavoured"?  KeTm,  buttlw'tTertcS'  S  dZ  ^^ 

hide  themselves,  or  ta^ke  to  fhe  wSer   if 'tW  ^^"^'^'''*«ly  endeavour  to 
person  approach  whilst  the  youngl^jJm  the  ttme  d.lt°^  ^ater,  should  any 

rmo#""'  ""^^  -  ^'^  — "-  i=nttfSrr  theS 


'\)t 


ORIGIN  AND  DEVELOPMENT  OP  INSTINCTS.  19^ 

played  an  important  part,  and  at  present  we  are  confining 
our  attention  to  the  evidence  concerning  the  formation  of 
secondary  instmcts,  or  the  mere  lapsing  of  intelligence  into 
instinct  without  the  aid  of  selection. 

We  see,  then,  that  the  instinct  of  wildness  may  be  eradi- 
cated   by  mere  disuse,  without    any  assistance  from  the 
pnnciple  of  selection,  and  further,  that  this  effect  persists,  or 
becomes  but  gradually  obliterated,  through  successive  genera- 
tions of  the  animals  when  feral,  or  restored  to  their  abori- 
ginal conditions  of  life.     Conversely,  it  has  now  to  be  shown 
that  instincts  of  wildness  may  be  acquired  by  the  hereditaiT 
transmission  of  novel  experiences,  also  without  the  aid  of 
selection.     This  is  shown  conclusively  by  the  original  tame- 
ness  of  ammals  m  islands  unfrequented  by  man,  gradually 
passing  into  an  hereditary  instinct  of  wildness  as  the  special 
experiences  of  man's  proclivities  accumulate ;  for  although 
selection  may  here  play  a  subordinate  part,  it  must  be  a  very 
subordinate  one.     Pages  might  be  filled  with  facts  on  thia 
head  from  the  writings  of  travellers,  but  to  economize  space 
1  cannot  do  better  than  refer  to  Mr.  Darwin's  remarks,  with 
their  appended  references  in  his  chapter  at  the  end  of  this 
volume.    To  these  remarks,  however,  I  may  add  that  the 
development  of  fire-arms,  together  with  the  growth  of  sportin<^ 
interests,  has  given  game  of  all  kinds  an  instinctive  know- 
ledge of  what  constitutes  "safe  distance,"  as  every  sportsman 
can  testify;  and  that  such  instinctive  adaptation  to  newly 
developing  conditions   may  take  place  without  much   aid 
from  selection  is  shown  by  the  short  time,  or  the  small 
number  of  generations,  which  is  sufficient  to  allow  for  the 
change— witness,  for  instance,  the  following,  which  I  quote 
from  the  paper  on  "Hereditary  Instinct"  by  the   careful 
observer  Andrew  Knight:— "I  have  witnessed,  within  the 
period  above  mentioned,  of  nearly  sixty  years,  a  very  great 
change  m  the  habits  of  the  Woodcock.     In  the  first  part  of 
that  time,  when  it  had  recently  arrived  in  the  autumn,  it  was 
very  tame;  it  usually  chuckled  when  disturbed,  and  took 
only  a  very  short  flight.    It  is  now,  and  has  been  during 
many  years,  comparatively  a  very  wild  bird,  which  generally 
rises  in  silence,  and  takes  a  comparatively  long  flight,  excited 
1  conceive,  by  increased  hereditary  fear  of  man."* 

•  Phil.  Trans.,  1837,  p.  369. 


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198 


MENTAL  EVOLUTION  IN  ANIMALS. 


instfnctfwheZ  nf  /?^"'"''  "^  ^'''^^y  ^"  ^^'  ^^^^^^  of 
instinct  (whether  of  the  primary  or  secondary  class^  is  Der- 

haps  most  strongly  manifested  in  the  effects  of^  cross  n^  ^ll 

18  not  indeed,  easy  to  obtain  this  class  of  evidence  In  the 

rrl^'^^'p^fT'^'^^^.^i^y^^^^  ^^^^«  i-  a  sfate  of  lire 
onP  Tf,;.i  V''^"''  ^  r^^  'P^^^^«  i«  crossed  with  a  tame 
one,  It  usually  happens  that  the  hybrid  or  mon-rel  Droorpnv 

e^vid^ni"  ^^r^'i  Psycho?°»^-      ^^d  stiU  m^e  ?og^^^^^^^^ 
evidence  of  such   blending  when  two  different  hrppiV^? 
domesticated  animals  are  Lssed.  havLg  dTveTse  heredttarv 
habits,  or  as  Mr  Darwin  calls  them,  "domes  c  instincts^ 
Thus  a  cross-breed  between  a  setter  aid  a  poLter  wi  1  blend 

Wr'S'AK^!^'^''?^  worldngpec'uliLto^ese  two 
breeds,  Lord  Alford's  celebrated  strain  of  ereyhounds  ao 
qmred  much  courage  from  a  single  cross  witf  a  buU  do.   * 
and  a  cross  with  a  beagle  "generations  blck  will  give  to' I 
spaniel  a  tendency  to  hunt  hares."t  ^ 

vn„^^T'  •^°'^!'^  '^^'  •-"  I"^  one  instance  I  saw  a  verv 
young  dog,  a  mixture  of  the  Springing  Spaniel  aid  SpTI? 
which  dropped  upon  crossing  the  track  of  rSrM.e  af  ?ts 
male  parent  would  have  don^and  sprangthe  M  in^sCe 
a  WoodcocT  i'lp  ^r "^  "  '^'"PJ^  ''  ^^'^«  afterwards  found 
;a:^»Ce  &  S7h  ^^IC^^Z  t'T^ 
rSvrm1i\ton^^^'  and  the  experiments  and  o&^Z 
Lerlsti^l"'  ""^'^  '^'"^  ^"^^  ^^*  ^^^^  ^'^y  ^^nierous  or 
,     On  this  point  Mr.   Darwin   writes :~« These  dnmPQHn 

in^l5.    '     a  r    "^,  "^®  manner  become  curiously  blended 

straight  line  to  his  master  when  called."!  Some  further 
remaiKs  on  this  subject  wiU  be  found  in  Mr  DaSs 
appended  essay  on  instinct;  and  here  I  may  fit^y  conekde 
the  present  chapter  by  quoting  the  foUowinc.  parTaraDh 
which  occurs  in  another  part  of  WsMSS.  Paragraph 

•  Touatt  on  Dog,  p.  311. 

t  Blaine,  Rural  Sports,  p.  863,  quoted  by  Darwin. 

I  Ongm  0/ iSpecies,  p.  210.  ^     u^wia. 


,fi 


ORIGIN  AND  DEVELOPMENT  OF  INSTINCTS. 


199 


In  Chapter  VII  I  have  given  some  facta  showing  that 
when  races  or  species  are  crossed  there  is  a  tendency  in  the 
crossed  offspring,  from  quite  unknown  causes,  to  revert  to 
ancestral  characters.      A  suspicion  has  crossed  me  that  a 
shght  tendency  to  primeval  wildness  sometimes  thus  appears 
m  crossed  animals.    Mr.  Garnett  in  a  letter  to  me  states  that 
his  hybrids  from  the  musk  and  common  duck  'evinced  a 
singular  tendency  to  wildness.'      Waterton    ('  Essays  on 
Natural  History'  p.   197)  says  that  in  his  dick,  a  cross 
between  the  wild  and  the  tame,  'their  wariness  was  quite 
remarkable.       Mr.   Hewitt,   who  has   bred    more    hybrids 
between  pheasants  and  fowls  than  any  other  man,  in  letters 
to  me  speaks  m  the  strongest  terms  of  their  wild,  bad,  and 
troublesome  dispositions;   and  this  was  the  case  with  some 
which  I  have  seen.      Captain  Hutton  made  nearly  the  same 
remark  to  me  in  regard  to  the  crossed  offspring  from  a  tame 
goat  and  a  wild  species  from  the  western  Himalaya.      Lord 
Powis   agent,  without  my  having  asked  him  the  question 
remarked  to  me  that  the  crossed  animals  from  the  domestic 
Indian  J3uU  and  common  cow  '  were  more  wild  than  the 
thorough-bred  breed '      I  do  not  suppose  that  this  increased 
wildness  IS  invariable;    it  does  not  seem  to   be  the  case 
according  to  Mr.  Eyton,  with  the  crossed  offsprin<T  from  the 
common  and  Chinese  geese;   nor,  according  to  Mr.  Brent 
with  crossed  breeds  from  the  Canary."  ' 


r  t  ■■ 


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200 


MENTAL  EVOLUTION  IN  ANIMALS. 


'i;i 


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■«^;     .  <:» 


lib*!' 


-It  "- 


CHAPTER  XIIL 

Instinct  (continued). 

Blended  Origin,  or  Plasticity  of  Instinct. 

e^Sistd'- ^"""«"  '"^"^^^^"  ''  ^^y'  I  t^-k,  be  taken  as 

tions,  tumbl  „g  Stumble  "leoLTr'!'";^  "'"?'''"  "'T^'" 

be  fixed  and  improved  by  natural  selection;  wh™  tSfiled 
Wnt  re™«t,n5r""'"''  ?"g'°?l'y  intelligent  may   by 

j^rfrSi?:-biTj'"X^?l£ 

«rMtinnfn»1 '5^  T  "^  ""i"*''' o^"  P-^^- ha»  - 
to  pro3TweU  a,  fb>«'"?  "1  cats-being  transmitted 
t„  fh.  i„!^i?  ^i  ^  "^*  ™°''*  instructive  facts  with  rewd 
to  the  loss  of  wildness  by  certain  domesticated  animals  and 

shnT'p^Sf  rf  "'  "^n^'^""'  "y  animrrhabiting 

p:£:zi:fsT^^'i  iS^titii  £s:  i! 


:[ii 


BLENDED  ORIGIN,  OR  PLASTICITY  OP  INSTINCT.  201 

Although  for  the  sake  of  clearness  I  have  so  far  kept 
separate  these  two  factors  in  the  formation  of  instinct  it  has 
now  to  be  shown  that  instincts  are  not  necessarily  confined 
to  one  or  other  of  these  two  modes  of  origin  exclusively  •  but 
on  the  contrary,  that  instincts  may  have,  as  it  were,  a  double 
root—the  principle  of  selection  combining  with  that  of 
lapsing  intelligence  to  the  formation  of  a  joint  result  Thus 
heredita-y  proclivities  or  habitual  actions,  which  were  never 
intelligent  but,  being  useful,  were  originally  fixed  by  natural 
selection,  may  come  to  furnish  material  for  further  improve- 
ment, or  be  put  to  improved  uses,  by  intelligence;  and  con- 
versely, adjustments  originally  due  to  lapsed  intelligence 
may  come  to  be  greatly  improved,  or  put  to  improved  uses, 
by  natural  selection. 

As  an  example  of  the  first  of  these  complementary  cases 
—or  that  of  a  primary  instinct  modified  and  improved  by 
intelligence—let  us  regard  the  case  of  the  caterpillar  wliich 
before  changing  into  a  crysalis,  crosses  a  small  space  with  a 
web  of  silk  (to  which  the  crysaHs  can  be  firmly  suspended), 
but  which  when  placed  in  a  box  covered  with  a  muslin  lid 
perceives   that  this  preparatory  web  is   unnecessary,   and 
therefore  attaches  its  crysalis  to  the  already  woven  surface 
supplied  by  the  muslin;*   or  let  us  regard  the  case  of  the 
bird  described  by  Knight,  which  observed  that,  having  placed 
her  nest  upon  a  forcing  house,  she  did  not  require  to  visit  it 
during  the  day  when  the  heat  of  the  house  was  sufficient  to 
incubate  the  eggs,  but  always  returned  to  sit  upon  the  e^sa 
at  night  when  the  temperature  of  the  house  feUf      In 
both  these  cases  of  primary  instincts  modified  by  intellifrent 
adaptation  to   particular  circumstances— and   hundreds  of 
others  might  be  added— it  is  evident  that  if  the  particular 
circumstances  were  to  become  general,  the  adaptation  to  them 
becoming  likewise  general,  would  in  time  become  instinctive 
by    lapsed    intelligence:     if   muslin    and    forcing    houses 
were  to  become  normal  additions  to  the  environment  of 
the  caterpillar  or  the  bird,  the  former  would  now  cease  to 
build  Its  web,  and  the  latter  cease  to  incubate  her  eggs  by 

*r,«lf/®-  ^"f^  ""?  u  P^""®'  ■^'»f?»"'%^.  ■^ol.  ii,  p.  476.  It  is  evident  that 
the  weaving  of  a  web  by  a  caterpillar  adapted  to  the  needs  of  its  future  con. 
dition  as  a  frvsalis,  must  be  due  to  instinct  of  the  primary  kind,  inasmuch  aa 
no  individual  caterpillar  prior  to  the  formation  of  such  a  struc  ure  can  W 
known  by  expenence  what  it  is  to  be  a  crysalis. 
t  Loc.  cit. 


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MENTAL  EVOLUTION  IN  ANLMALa 


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■jh 

tuh'  i"Jevt,S  '  '.^;™'''"7  instinct  w,mMbeeomo  Mendea 
act  of  intelli;rence      Bi,f  /^f  f  burrowing  was  probably  an 

ciples  ^  *^^^  J"""'^  operation  of  both  prin- 

•  Tbo  taott  .1  ;  iiis  case  have  been  told  me  by  Dr.  Eae,  P.R.S. 


BLENDED  ORIGIN,  OR  PLASTICITY  OP  INSTINCT.  203 

this  further  development  of  an  instinct,  if  the  variations  of 
the  instinct  are  not  wholly  fortuitous,  btit  arise  asTnS  '  ^t 
adaptations  of  ancestral  experience  to  the  perceived  requ  re 
inents  of  individual  experience.  i^4""o- 

Trusting  then  it  is  sufficiently  clear  that  the  two  princi-  • 
pies  which  may  operate  either  singly  or  torretherinfoim.nl 
instincts  may  operate  together  wWchevor^'of  the  two  maf 
I  n?n?in°  5.T'  '"^  "'Y  P^^ticular  case.  the  historical  priority. 
I  may  m  future  neglect  to  entertain  the  question  of  8u4 
prionty;  without  considering  whether  in  this  and  that  case 
seection  was  prior  to  lapsing  of  intelligence,  or  lapsTuro? 
n  elligence  was  prior  to  selection,  it  wiU%e  enough  t^o  p;;,ve 
that  the  two  principles  are  conjoined  ^ 

ihJlJ^T^  ^)''  '^-  ^T  ^°  «^«^'  ™uch  more  copiously 
than  has  been  done  m  the  above  two  or  three  illustration  J 
not  only,  as  was  proved  in  the  previous  chapter,  that  fu  ly 

may  be  determined  by  intelligence.  y^imiwu 

Plasticity  of  Imtind, 

fL  ^"  fo™P!"^PwWications  I  have  used  this  teiw  to  express 
the  modifiabihty  of  instinct  under  the  influenee  of  i^lZnce 
I  sha  1  now  give  some  chosen  inslances  of  such  ^^d  Smy 
and  then  proceed  to  indicate  the  causes  which  most  fre- 
quently lead  to  intelligence  thus  acting  upon  instinct  It  is 
of  importance  that  I  should  begin  by  rendering  the  fact  of 
he  plasticity  of  instinct  beyond'que  Jion,  no  only  becfuse 
alterabl^  'ilT'^  the  prevalent  n'otion  thit  instincL  ar  u" 
alterably  fixed,  or  rigidly  opposed  to  intelligent  alteration 
under  changed  conditions  of  life;  but  also  because  iuTthit 
principle  of  plasticity  that  largdy  suppHes  to  na  ural  e 
tion  those  variations  of  instinct  in  beneficial  lines,  which  are 

Huber  observes:  "How  ductile  is  the  instinct  of  bees 
and  how  readily  it  adapts  itself  to  the  place,  the  c  rcum- 
stances.  and  the  needs  of  the  community  " 

aiJ^  ^Yl  "f-^i^®  '^^^  ""^  ^'^  ^"^«^«ls  in  which  instinct  has 
at  amed  its  highest  perfection  and  complexity,  even  wSiout 
evidence  we  might  be  prepared  to  expect  that  instinct  I 
everywhere  ductile.     Moreover  the  bees  constitute  a  good 


i 


11 


!»,f  ' 


i     li 


:  ■  1 

i 

1 

'hi  m 

1 

1 

.,    11 
ill 

i 

1 

w 

1 

204 


MENTAL  EVOLUTION  IN  ANIMALS. 


'ii'-i 


^■i' 


if  I  ;. 


s?;?™V"  Anil's  zr""'  nr''-  '""="'^'  ^  I  i^e 

fivo^     Pripay  kmd;   yet,  as  we  shaU  see,  though  so  wpII 
™«t\?Wst- "'■  ''^'^"'"S  the  observation,  of  Huber, 

combs  of  old  wal  and  they  h^d  ^Ih^^^^^^^^^ 

Lm"r^'/l  ^i""^^  favourable  season  they  would  not 
have  hesitated  to  build  a  new  comb  upon  the  old  or  but  ?t 
being  inexpedient  at  that  period  to  expend  the^  mo  vision  of 

stSv'of^V^'r"^  ^^.T'  th%\3d°irth1 
scaoiiity  ot   the    faUen    comb    by  another  process     Tbpv 

furmshed  themselves  with  wax  from  the  other  combs   bv 

wicn  repairing  the  accidents  which  their  masonrv  had  pv 

old  wax,  and  forming  numerous  ties  and  braoes  to  unite  them 
tbT  tharwas^^t'lt"  '""^. '°  "?!'  ™"^  ofVerhabi  a" 
ia  the.^X7.i'lrara  p^dta,^"^::^^^^^^^^^ 


f. 


BLENDED  ORIGIN,  OR  PLASTICITY  OF  INSTINCT.  205 

"Haying  placed  in  front  of  a  comb  which  the  bees  were 
constructing  a  shp  of  glass,  they  seemed  immediately  aware 
that  It  would  be  very  difficult  to  attach  it  tososlppeTva 
surface,  and.  instead  of  continuing  the  comb  in  a  stSht 
line,  they  bent  it  at  a  right  angle,  s^  as  to  extend  beyond  the 
slip  of  glass,  and  ultimately  fixed  it  to  an  adjlLTpart  of 
«ie  woodwork  of  the  hive  which  the  glass  did  not  cover 
This  deviation  if  the  comb  had  been'a  mere  smple  and 
un  form  mass  of  wax,  would  have  evinced  no  small  ingenuity 

or  fno.  n7    i^']f  '"  "^^r^  '^'''  ^  «°™b  consists  on  elch     de' 
or  face  of  cells  ha  nng  between  them  bottoms  in  common 
and  If  you  take  a  comb,  and,  having  softened  the  w^x  bv 
heat,  endeavour  to  bend  it  in  any  pa?t  at  a  rioht  an^e  vou 
will  then  comprehend  the  difficifltL  winch  our  liSrardi^ 
tects  had  to  encounter.     The   resources  of  their  instint 
however,  were  adequate  to  the  emergency.     They  made  the 
cells  on  the  convex  side  of  the  bent  part  of  theTomb  much 
iTff'  ^^^  .tl^oseon  the  concave  much  ..m^/cr  than  uTual 
latte%'ut  ;?•"""  three  or  four  times  the  diameter  oS 
lat  er     But    his  was  not  all.     As  the  bottom  of  the  small 
and  large  cells  were  as  usual  common  to  both,  the  cells  were 
not  regular  prisms,  but  the  smaller  ones  considerably  wider  at 
the  bottom  than  at  the  top.  and  conversely  in  tL  W 
ones !     What  conception  can  we  form  of  so  wonderfur  a 

nS     1^^.?^  '"'^?'^-     ^"^^'  ^'  Huber  asks,  can  we  com- 
prehend the  mode  in  which   such  a   crowd  of  iXuTe^s 
occupied  at  the  same  time  on  the  edge  of  a  comb,  coidd  aoS 
to  give  1  the  same  curvature  from  on?  extremity  o  the  other 
or  how  they  could  arrange  together  to  construct  on  one  face 
cells  so  small,  while  on  the  other  they  imparted  to  them 
such  enlarged  dimensions  ?    And  how  can  w^  S  adeo  1 
astonishment  that  they  should  have  the  art  of  makit^cd 
of  such  different  sizes  correspond  ?  "  *  ° 

Other  observations  of  Huber  show  that  even  under  ordi- 
nary  circumstances    bees    are   frequently  in   the  habit  of 

the  cells  winch  are  destined  to  receive  drones  requirinrr  to  be 
cousiderably  larger  than  those  which  are  destined  to  ?e  eive 
neuters,  and  the  rows  of  all  the  cells  being  conunuous.  where 
j^     *  Kirhy  and  Spence,  loc.  cit.,  pp.  485-495. 


I'c^3l 


■t, 
;'  i 


mm 


206 


ti  i; 


t  , 


I  f  tl 


>i        1  • 


'Hi 


■  I   ■ 


f'^iiii 


MENTAL  EVOLUTION  IN  ANIMALS. 


a  transition  takes  place  from  one  class  of  cell  to  the  otiier  a 
complex  geometrical  problem  arises  how  to  unite  hexagonal 
ceUs  of  a  small  with  others  of  a  large  diameter,  without 
Jhr^f  fy^id  spaces  or  interfering  with  the  regularity  of 
the  comb.  Without  occupying  space  with  what  would 
necessarily  be  a  rather  lengthy  exposition  of  the  manner  in 
which  the  bees  solve  the  problem,  it  is  enough  to  say  that 
m  passing  from  one  form  of  cell  to  the  other,  they  require  to 
construct  a  great  many  rows  of  intermediate   cells\vhich 

other     wll  "ft  t'  '"'"^  '^'  °^^^"^^>^  ^«"«'  b"<^  from  each 
other     ^hen  the  bees  arrive  at  any  stage  in  this  process  of 

tr:vtT;oMV"^^''''tP  ''  '''''  '''"^'  -^  continue  ?o  build 
the  whole  of  their  comb  upon  this  pattern.     But  they  inva- 

r  ably  proceed  from  one  stage  to  another  until  the  transS 

effected.      On  this    subject    Kirby    and    Spence    remark: 
Reaumcr,  Bonnet,  and  other  naturalists  cite  these  irre^ui 
laiities  as  so  many  examples  of  imperfections.     What  woSld 
mTof'Jh  their  astonishment  if  they  had  been  aware  thlt 
pait  of  these  anomalies  had  been  calculated   (?  adaptive)  • 
that  there  exists  as  it  were  a  moveable   harionyTn  the 
mechanism  by  which  the  cells  are  composed  !    .      ^      It  i! 
far  more   astonishing  that  they   know  how  to  qr4  the? 
ordinary  rout.ne  when  circumstances  require  thai  they  should 
build  male  cells :    that  they  should  be  instructed  to  vary  the 
dimensions  and  the  shape  of  each  piece  so  as  to  return  to  a 
regular  order;  and  that,  after  haviig  constructed  thirty  or 
fnSiJnhfr  "^  '''^^%''^\'^'^y  again^ave  the  regular  o^der 
?n^,    A    ^^  were  formed,  and  arrive  by  successfve  diminu- 
tions at  the  point  from  which  they  set  out  Hpl 
again  as  observed  in  a  former  instance,  the  wonde;  would  be 
less  If  ,^,,.^  comb  contained  a  certcvin  number  of  transition 

mrtof  7t    bu't1l'-''"''r'J^"'l^^^^^  ^^  ''''  ^''^  the  saZ 
part  ot  It;  but  this  is  far  from  being  the  case.     The  event 

whicn  alone,  at  whatever  period  it  may  happen    se'ms  to 

of  tr  reen'  t^  1*°  ""'^f  "^^^-  ''^''  - '^  -^polion 
0    the  queen.     So  long  as  she  continues  to  lay  the  e<vrrs  of 

worke,s,  not  a  male  cell  is  provided;  but  as  soon  as  ste  t 

about  to  lay  male  eggs,  the  workers  seem  aware  of  it   and 

you  then  see  them  form  their  cells  irregularly" 

Here  then  we  have  concerted  variation  in  the  mode  of 

constructing  the  cells  of  a  normal  and  definite  kind,  ^nd  we 


BLENDED   OKIOIH,  OK  rLASUCITY  OP  IKSIINCT.  207 

in  the  operation  of  s  t!li^ziSk  e^:::''J:^^;: 

the  formation  of  the  comb  so  f-lmf  ^,.1,..:  •  P^'^^^icity  m 

"  moving  harmony  "  uTl'^l  ctl^  ^  S "anTitdo'e: 

of  a  primary  instfnorb  Sg  ^^  tty  m'odtd  bv  Sr  "*"" 

direction  of  buUding  them  r«4«ired  to  reverse  the 

whirh\ra?so'7uftoZ'lL*"  '^  '°"»"'"""  "bservations.     ' 

thi.  could  hardly  have  occurred  iSure  »"''  '"  '°°"*^'"  ^ 


1 1 


"I.    :  '^ 


i  i 


!^l' 


!)      -» 


W-  'l 


1  <','*' 


ilpl 


208 


MENTAL  EVOLUTION  IN  ANIMALS. 


a  flatted  mass,"  which  they  used  as  moss.  Again,  Andrew 
Knight  observed  that  his  bees  availed  tliemselves  of  a  kind 
of  cement  made  of  wax  and  turpentine,  with  which  he  had 
covered  decorticated  trees— using  this  material  instead  of 
their  own  propolis,  the  manufacture  of  which  they  discon- 
tinued ;*  and  more  recently  it  has  been  observed  that  bees, 
"instead  of  searching  for  pollen,  will  gladly  avail  themselves 
of  a  very  different  substance,  namely,  oatmeal."  f 

Again,  Osmia  auridenta  and  0.  hicolor  are  species  of  bees 
which  construct  tunnels  in  hard  banks  of  earth  or  clay,  in 
which  they  afterwards  deposit  their  eggs— one  in  each  parti- 
tioned cell.  But  when  they  find  tunnels  ready-made  (as  in 
the  straws  of  a  thatched  roof)  tliey  save  themselves  the 
trouble  of  employing  their  instincts  in  the  way  of  tunnel- 
making— merely  building  transverse  partitions  in  the  tube  to 
form  a  series  of  separate  cells.  It  is  specially  remarkable 
that  when  they  thus  utilize  the  whorl  of  an  empty  snail-shell, 
the  number  of  cells  which  they  partition  off  is  reguhued  by 
the  size  of  the  shell,  or  the  length  of  the  whorl.  Moreover, 
if  the  whorl  proves  too  wide  near  the  orifice  of  the  shell  for 
its  walls  to  constitute  the  boundaries  of  a  single  cell,  the  bee 
will  build  a  partition  at  right  angles  to  the  plane  of  the 
others,  so  forming  a  double  cell,  or  two  cells  side  by  side.l 

Now,  in  all  these  cases  it  is  evident  that  if,  from  any 
change  of  environment,  such  accidental  conditions  were  to 
occur  ordinarily  in  a  state  of  nature,  the  bees  would  be  ready 

•  Phil.  Trans.,  loc.  cit, 

t  Origin  of  Species,  p.  228.  It  is  interesting  in  connection  with  these 
facts  to  note  how  singularly  well  they  happen  to  meet  a  criticism  of  Kirby 
and  bpence,  which  was  advanced  before  thev  had  been  observed,  with  the 
obiect  of  discrediting  the  view  of  instinct  being  modified  by  inteUigence. 
Ihese  authors  ask  {loo.  cit,  vol.  ii,  p.  497),  why,  if  such  were  the  case,  should 
not  bees  sometimes  be  found  to  use  mud  or  mortar  instead  of  precious  wax  op 
propolis :  "  Show  us,"  they  say,  "  but  one  instance  of  their  having  substituted 
mud  tor  propolis  ....  and  there  could  be  no  doubt  of  their  havint' 
been  guided  by  reason."  It  is  curious  that  this  demand  should  so  soon  havS 
been  met  by  so  apposite  an  observation.  Doubtless  mud  is  not  so  good  a 
miterial  for  the  purposes  required  as  propolis,  but  as  soon  as  the  bees  are 
turmshed  with  a  substance  that  is  as  good,  they  are  ready  enough  to  prove 
their  reason,  even  to  the  satisfaction  of  what  was  supposed,  a  priori  a 
crucial  test.  This  case  should  serve  as  a  warning  against  the  use  of  the  ques- 
tion-begging argument,  which  where  any  degree  of  evidence  is  presented  of 
intelligence  compounded  with  instinct,  forthwith  raises  the  standard  and  savs 
--yhow  us  an  animal  doing  this  or  that,  which  would  be  still  more  remark- 
able, and  then  we  shall  bo  satisfied. 

X  See  F.  Smith,  Catol.  Brit.  Hymenoj^tera,  pp.  159-60. 


BLENDED  ORIGm,  OR  PLASTICIIT  OF  INSmCT  209 

cloth,  of  8ubstitu^i„rcernwt  "'  '^'''^^"^  '^''''^''  «f 
pollen.  °       "^"""^  *°^  propolis,  or  oatmeal  for 

Dr.  Leech  gives,t  on  the  authority  of  Sir  T  Ppr,to 
of  a  web-spmn  ng  spider  whiVh  wi  i    .  2     J- /^anks,  a  case 
as  a  consequence  could  onlJl  '^-  ^"^^  °^  ^^^  ^^S^'  ^n^^- 

observed  to^doptihfhabitrorth?'rT-P'^'^^^'>-  ^^  ^^'^« 
does  not  build  a  web  but  en m1  f  ^''"V''-  'P^^^^'  ^^ich 
change  of  habit,  howeve  wis  onlvl  ^'"^  ^^  '''^^'^"-  ^^^^ 
recovered  its  legs  after  m^rit'^R^'P.^'"'^'  '^  "^^  «P'^^«r 
this  case  that,  so  far  as  Te  n  n.H..-.  p  •^'''"''  "^'^^"^  f^'O"^ 
the  web-spinninc.  spider  wo'St^  ^  "''^'"'^  ^'  concerned, 
the  habit  of  hunting  if  7or  .1  ''^"^^-^^  ^">^  <^^"^«  ^o  adop 
to  build  a  webJ^^;;a''t^^-3^^?/b!"-/^V'°l^'  "^'  ^'  ^^^ 
m  the  life-time  of  an  individual    ^     ^       '''^'^'''  transition 

that'rir;.^^^^^^^  -  -y  easily  .nd 

sake  of  brevity,  I  shall  rnnfino  il*     ^""^  ^^^6'  ^^r  the 

from  the  oldest  most  constant  an^^if  ^'  '''''''''''  ^^^^^ 
most  fixed  of  the  instincts  whLv'  f  f'^^'f '  P^'^^^^^bly  the 
viz.,  the  maternal  ''^  vertebrated  animals  display, 

that^S^^^^Si  ^:^^  '''^  P--^-^  chapter 
We  have  now  te  TZ^kthat:^o^^^^^ 
from  the  ancestral  modes  are  not tr^'lV'"''  ''  ^'"^^^'^'^^ 
caprice,  bat  sometimes'^' i^Ct^^^^^^^^^ 

.      *  See  Anmal  InteUwence  from  xc\^in\.  r 

ing,  m  order  to  show  briefly li.atTnf^Ju^  J  T^  '^f  """-^  'J"°*«  t''*  fo"ow- 
present  a  "moving  harrnonv"  Jwvf  ^         ^*  "'"'''^  ^^s-  cr  more  than  bees 
"  The  characteristic'  ^r^oJ^he  bui ^^^0??' r'.'°°  ""' ^'"^  archit.  tare  :-!! 
complete  absence  of  an  unclmngeab  e  SJ  l^V r  "T  ^""''^^  " ''  '^^  ^''"ost 

little  perfect  work  to  circumstances  and  to  hI«  ,  ^T  *^  '"^^  "^^ir  indeed 
?v  nVr  '^'.^  '""'•''^  f°^  i^^elf  on  a  given  Sa^  nn.l  "''"'T"  "^  '^'^  situation, 
by  others  when  they  understand  its"^  an'^t'S)  "  "''^^  "-"^^ionally  aided 

bj  Mr.  Darwin  in  the  Appendix.        '  ^"    ^'*-     "^^'^  ^'^^'^  «  briefly  aUuded  to 


:ii; 


•; '  1 


T" 


■  M  , 


M 


1^:  J 


■  ^  'I 


II, 


II' 


210 


MENTAL  EVOLUTION  IN  ANIMALS. 


( .' 


>  > 


Mi 


iHl 


lUii 


show  this,  it  will  be  sufficient  to  state  the  following  in- 
stances. 

Thread  and  worsted  are  now  habitually  used  by  sundry 
species  of  birds  in  building  their  nests,  instead  of  wool  and 
horsehair,  which  in  turn  were  no  doubt  originally  substitutes 
for  vegetable  fibres  and  grasses  ;  this  is  specially  noticeable 
in   the   case  of  the  tailor-bird  and   Baltimore  oriole,   and 
Wilson  believes  that  the  latter  improves  in  nest-building  by 
practice— the  older  birds  making  the  better  nests.    The  com- 
mon house-sparrow  furnishes  another  instance  of  intelligent 
adaptation  of  nest-building  to  circumstances  ;  for  in  tree°s  it 
builds  a  domed  nest   (presumably,  therefore,  the  ancestral 
type),  but  in  towns  avails  itself  by  preference  of  sheltered 
holes  in  buildings,  where  it  can  afford  to  save  time  and 
trouble  by  constructing  a  loosely  formed  nest.     A  similar 
case  is  furnished  by  the  gold-crested  warbler,  which  builds 
an  open  cup-shaped  nest  where  foliage  is  thick,  but  makes  a 
more  elaborate  domed  nest  with  a  side  entrance,  where  the 
site  chosen  is  more  exposed.     Moreover,  the  chimney  and 
house-swallows   have  taken   to  building  in   chimneys  and 
under  the  roofs  of  houses  by  way  of  an  intelligent  or  plastic 
change  of  instinct,  and  in  America  this  change  has  taken 
place  within  the  last  three  centuries  or  less.     Indeed,  accord- 
ing to  Captain  Elliott  Coues,  all  the  species  of  swallow  on 
the  American  continent  (with  one  possible  exception)  have 
modified  the  structure  of  their  nests  in  accordance  with  the 
novel  facilities  afforded  by  the  settlement  of  the  country ;  for 
he  writes : — 

"  Various  species,  indeed,  now  regularly  accept  the  arti- 
ficial nesting-places  man  provides,  whether  by  design  or 
otherwise.  Such  is  notably  the  case  with  several  kinds  of 
Wrens,  with  at  least  one  kind  of  Owl,  with  one  Bluebird,  the 
Pewit  Flycatcher,  and  especially  the  House-sparrow.  Various 
other  birds  occasionally  avail  themselves  of  like  privileges, 
still  retaining  in  the  main  their  original  habits.  But  in  no 
other  case  than  that  of  the  Swallows  is  the  modification  of 
habit  so  profound,  or  so  nearly  without  exception  throughout 
the  entire  family.  ...  All  of  our  Swallows  have  been 
modified  by  human  agency,  excepting  the  Bank  Swallow. 
....  Some  of  them,  like  the  Purple  Martin  and  the 
Violet-green  Swallow,  are  still  surviving  their  apprenticeship 
under  the  new  re(/ime,  which  the  settlement  of  the  country 


ilr 


BLENDED  ORIGIN,  OK  PLASTICITY  OP  INSTINCT.  211 

has  brought  about.  .  .  .  Those  whose  acquired  habits 
have  become  thoroughlj' ingrained  are  now  pretty  constant  in 
their  adherence  to  a  single  plan  of  architecture;  but  the 
Violet-green  Swallow,  for  instance,  at  present  nests  in  a  very 
loose  fashion,  according  to  circumstances."  * 

The  statement  made  in  1870  by  the  distinf^uished 
naturalist  Pouchet  to  the  effect  that  within  the  same  interval 
of  half  a  century  the  house-swallow  had  materially  altered  its 
mode  of  nest-building  at  Eouen,t  was  subsequently  shown  by 
M.  Noulet  to  be  erroneous  ;i-  but  this  passage  which  I  have 
quoted  from  Captain  Elliott  Coues  is  sufficient  to  show  that 
facts  analogous  to  those  stated  by  M.  Pouchet  have  occurred 
among  many  species  of  the  swallow  tribe. 

In  "  Animal  Intelligence "  I  gave  some  cases  of  the 
remarkable  intelligence  which  is  displayed  by  certain  birds 
when  they  remove  their  eggs  or  their  young  from  places 
where  they  have  been  disturbed  (pp.  288-9),  and  I  added  the 
remark  that  it  is  easy  to  see  that  if  any  particular  bird  is  in- 
telligent enough,  as  in  the  cases  quoted,  to  perform  this 
adjustive  action  of  conveying  young— whether  to  feeding- 
grounds,  as  in  the  case  of  the  hen,  or  from  sources  of  danger, 
as  m  the  case  of  partridges,  blackbirds,  and  goat-suckers— 
inheritance  and  natural  selection  might  develop  the  originally 
intelligent  adjustment  into  an  instinct  common  to  the  species. 
And  it  so  happens  that  this  has  actually  occurred  in  at  least 
two  species  of  birds— viz.,  the  woodcock  and  wild  duck,  both 
of  which  have  been  repeatedly  observed  to  ±ly  with  their 
young  to  and  from  their  feeding-ground. 

Since  writing  the  above,  I  have  found  among  Mr.  Darwin's 
MSS  a  letter  from  Mr.  Haust,  dated  New  Zealand,  December 
9th,  1862,  and  stating  that  the  «  Paradise  Duck,"  which 
naturally  or  usually  builds  its  nest  along  the  rivers  on  the 
ground,  has  been  observed  by  him  on  the  east  of  tlie  island 
when  disturbed  in  their  nests  upon  the  ground,  to  build  "  new 
ones  on  the  tops  of  high  trees,  afterwards  bringing  their  younw 
ones  down  on  their  backs  to  the  water,"  and  exactly  the 
same  thing  has  been  observed  of  the  wild  ducks  of  Guiana.  § 
Now,  if  intelligent  adjustment  to  peculiar  circumstances  is 

*  mrds  of  Colorado  Valley,  pp.  292-4.      +  Comptes  Eendus,  Ixx,  p.  492 
I  Ihid.,  Ixxi,  p.  78.     In  the  first  edition  of  Animal  Intelligence  I  quoted 
thig  statement  of  Pouchet  without  knowing  that  it  had  been  questioned 
§  toee  Oeol.  Journ.,  vol.  iv,  p.  325. 


ii 


11 


212 


MENTAL  EVOLUTION  IN  ANIMALS. 


!,       1 


'i\:      ' 


I   :    , 


UDon  t^TV^  °°^^  *^  "^^'^^  ^  bird  transport  her  young 

her  neft  on  n  T  v.  ^."^  ""r^",  ^  web:footed  water-fowl  build 
if  the  need  nf^  ^''''J  ^'"^^  ^^  ^^°  ^^^^  "«  do"bt  that. 
continuLo.  tt  '^V'^^^'^^^f^*  ^^^'«  ^^  sufficiently  long 
IT  r^f  '   ^  ^n^elhsenee  which  leads  to  it  would  eventu^ 

they  f  grSlty^:  c^SeS  e^nutbL^'Tt  Ts^^'' 

in  Jbati™°l"ZllT  "it  '"*"?'  °f  nidiflcation  to  that  of 
expenWs  wS  f     ^  '  '■'™  "  "^  """^  observations  and 

the  iJastioity  of  the  :nate,'ial  inSLrC  howa  lyLTaS 
that  the  instinct  was  directed  in  all  its  fnrPP  fn  fi.o  ^ 

Irood     Me  d'i?  Fr'T?  "'''  ™""'"''"  charaeterofth  eS 
DTOoa.    indeed,  It  is  just  because  of  this  evidence  thif   r 

Sf  '^T  T''  \"  *"  P'^^'^"'  »nnection  (or"thenvise  thev 
S  in  tSc   with  which'"  "'""P'"'^  "o-inielligenrvariaS 

by  the  manner  m  which  they  adapted  their  ancestral  instSs 
t  TW  ;»mias  tor  pmg.nj  whioh  .ri,e.  f,„m  jL.  pa,„^,  i„,u„c.  b,i„g 


BLENDED  ORIom.  OR  PLASTICITY  OF  INSTINCT.  213 

"  Spanish  hens,  as  is  notorious,  scarcely  ever  si>  nf  «11  •  K„f 
I  have  one  purely  bred  one  iust  now  f hoi  o!!       j  '  ^^^ 

Ihree  davs  nffpr  "Lj^viT  ^-     "^  u  "^^*^  ^'^^  ^^  dumm  es  for 

Spanish  chickeL"n  the  vLThpv'^^'^  '"  ""  'he 

of  all  a"e9  from  th,f  »/,?l   i,  .1    ^  ""^^  *"""'"  '"  number, 

iefuLT«prfuiitrt:'rhfckr  t-"°""",  ¥,'^  j"=' 

tliat  although  there\ve°eBrahmf„n;i  H   ",  ■•''""rl''''We,  too, 
happens  with  every  hen  that'hatehSs  out  a  brood  of  Zckli  "3  5 

domestic  animals,  is^pibably  ana£ fs%l  H  ''P"'°  '"'''  ^°g^'  '"'dothe; 
female  animals  adoptio'gthtyoun^^oTolL^s^e^^^  ^"^'^  ^"^  *^«  *-*  ^^ 

receWad'SLmTfS,  wh^  I'^rnowt  bf  "^^"^  ^''^°""*  ^^^''^  ^  ^-e 
jntbe^sesot^birdJin  a  -t'tTfltLltHE^rS^^^^^^^ 

fed  ;faS  S'sprot'  Tldetrril:  r;r^  ''''^^'  r^'^^  --  ^-« 

and  1  noticed  that  the  sparrow  contim^ed  tn  i  1 .,  '  ^''T^  ^'"^^  ^^^«  ^>-''"«. 
nest.     The  behaviour  ot' the  Lo  b  T  -  "i^'^.'ifter  thej  had  left  the 

bold  and  its  visits  to  the  nest  IZ.tr^      ,      ^^'^.  dissimilar,  the  wren  bemg 
its  visits  much  less  frcHluent  "  '       ''''''  '^'  'P'^™^  "'^^  ^^'7  ^^y  an! 

Pe.od  offour  months,Li  ti  £VS  SS^^J^^,:^:  ^^ 


i  ■:' 


S  .: 


II 


i   ill' 


1     i  •■ 


!  ;■ : 


I  ii: 


'f^il=i 


214 


MENTAL  EVOLUTION  IN  ANIMALS. 


iXli 


■;    i 


being  prolonged ;  for  a  pea-chick  requires  such  care  for  a 
very  much  longer  time  than  does  an  ordinary  chick.    As  the 
separation  between  a  hen  and  her  chickens  always  appears  to 
be  due  to  the  former  driving  away  the  latter  when  they  are 
old  enough  to  shift  for  themselves,  I  scarcely  expected  the 
hen  in  this  case  to  prolong  her  period  of  maternal  care,  and 
indeed  only  tried  the  experiment  because  I  thought  that  if 
she  did  so,  the  fact  would  be  the  best  one  imaginable  to  show 
in  what  a  high  degree  hereditary  instinct  may  be  modified  by 
peculiar  individual  experiences.     The  result  was  very  sur- 
prising    For  the  enormous  period  of  eighteen  months  this 
old  Brahma  hen  remained  with  her  ever-growin"  chicken 
and  throughout  the  whole  of  that  time  she  continired  to  pay 
It  unremitting  attention.     She  never  laid  any  eg^s  durinf^ 
this  lengthened  period  of  maternal  supervision,  anTif  at  any 
time  she  became  accidentally  separated  from  her  charge,  the 
distress  of  both  mother  and  chicken  was  very  great.     Even- 
tually the  separation  seemed  to  take  place  on  the  side  of  the 
peacock ;  but  it  is  remarkable  that  although  the  mother  and 
chicken  eventually  separated,  they  never  afterwards  forr^ot 
each  other,  as  usually  appears  to  be  the  case  with  hens  and 
their  chickens.     So  long  as  they  remained  together,  the 
abnormal  degree  of  pride  which  the  mother  showed  in  her 
wonderful  chicken  was  most  ludicrous ;  but  I  have  no  space 
to  enter  into  details.     It  may  be  stated,  however,  that  both 
before  and  after  the  separation  the  mother  was  in  the  habit 
of  frequently  combing  out  the  top-knot  of   her  son— she 
standing  on  a  seat  or  other  eminence  of  suitable  height,  and 
he  bending  his  head  forward  with  evident  satisfaction.     This 
fact  is  peculiarly  noteworthy,  because  the  practice  of  combiner 
out  the  top-knot  of  their  chickens  is  customary  amoncr  pea° 
hens.     In  conclusion,  I  may  observe  that  the  peacock  reared 
by  this  Brahma  hen  turned  out  a  finer  bird  in  every  way  than 
did  any  of  his  brothers  of  the  same  brood  which  were  reared 
by  their  own  mother,  but  that  on  repeating  the  experiment 
next  year  with  another  Brahma  hen  and  several  pea-chickens 
the  result  was  different,  for  the  hen  deserted  her  family  at 
the  time  when  it  is  natural  for  ordinary  hens  to  do  so,  and  in 
consequence  all  the  pea-chickens  miserably  perished."'* 
u  n}  ^l^^^®,.*^  ^^e  following  instructive  case  from  Jesse's 
Cleanings,  T  because  it  has  been  independently  and  uncon- 

•  Nature,  Oct.  28, 1875.  f  Vol.  i,  p.  98. 


s.r 


BLENDED  ORIGIN,  OR  PLASTICITY  OP  INSTINCT.  215 

Ml??VT^'''''^'^!?,  ^"^"'^  ^^^^^  ^y  »  correspondent, 
Mrs.  L.  MacFarlane.  of  Glasgow.  Indeed,  the  similaHty  is  so 
precise,  that  I  think  the  two  descriptions  must  refer  to  the  same 
incident ;  but  as  to  this  I  cannot  be  sure,  because  upon  my 
writing  to  Mrs.  MacFarlane  to  enquire,  she  answers  that  she 
is  not  able  to  inform  me.  However,  this  point  is  immaterial; 
for  my  correspondent  had  the  story  at  first  hand  from  the 
lady  to  whom  the  birds  belonged  (and  with  whom  she  was 
intimately  acquainted),  so  that  if  the  case  is  not  the  same  as 
the  one  narrated  by  Jesse,  its  repetition  is  so  exact  that  the 
same  description  applies  to  both  the  cases. 

"  A  hen,  who  had  reared  three  broods  of  ducks  in  three 
successive^  years,  became  habituated  to  their  taking  to  the 
water,  and  would  fly  to  a  large  stone  in  the  middle  of  the 
pond,  and  quietly  and  contentedly  watch  her  brood  as  thev 
swam  about  it     Tlie  fourth  year  she  hatched  her  own  e-4 
and  finding  that  her  chickens  did  not  take  to  the  wateHis 
the  ducklings  had  done,  she  flew  to  the  stone  in  the  pond,  and 
called  them  to  her  with  the  utmost  eagerness.    This  recollec- 
tion ot  the  habits  of  her  former  charge  is  not  a  little  curious  " 
My  correspondent,  Jlrs.  MacFarlane,  also  gives  me  another 
closely  similar  but  even  more  remarkable  case,  which  was 
observed  by  her  sister,  Miss  MackiUar,  of  Tarbert,  Cantyre 
In  this  case  a  hen  had  also  reared  thrc3  successive  broods  of 
ducklings  in  successive  years,  and  then  hatched  out  a  brood  of 
nine  chickens.    The  season  being  late,  she  was  confined  for 
some  weeks  till  the  chickens  became  strong  enough  to  face 
the  cold  weather.     Then,  in  the  words  of  my  correspondent, 
the  first  day  she  was  let  out  she  disappeared,  and  after  a 
long  search  my  sister  found  her  beside  a  little  stream  which 
her  successive  broods  of  ducklings  had  been  in  the  habit  of 
frequenting.      She   had  got  four  of  her  chickens  into  the 
stream  which  was  fortunately  very  shallow  at  tlie  time.     The 
other  five  were  standing  on  its  margin,  and  she  was  endea- 
vouring by  all  sorts  of  coaxing  hen-language,  and  by  pushin<T 
each  ^chicken  m  turn  with  her  bill,  to  get  them  into  the  wate? 

re  J^°°*  )^^^®.  ^f  ®^  ^*  ^^  ^^^^6^*  t^at  in  a  portion  of  the 
lifetime  of  an  individual  hen  there  may  be  laid,  by  inteUi- 
gent  observation  and  memory,  the  basis  of  a  new  instinct 
adapted  to  an  immense  and  sudden  change  in  the  habits  of 
progeny:  and  that  in  all  the  foregoing  cases  the  foster-mother 


m*il 


(^  ■ 


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( 

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if 

i  ' 

ril 


ua 

W: 

. 

i 

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'i      7 

I 

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11 

216 


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i   : 

1 

V.%  r  ' 

MENTAL  EVOLtlTIOlf  IK  ANIMALS. 


Tthe  fa    of  h    ?"•  "'"''^ '"'™""' "f  '■»  '^^'l. "  proved 
UarenuirempJf,n '■;*'. "'"P'"'  l»^' "<^'i»ns  to  their  peeu 
i^^JxptatlZSf  :.o  ^tvrt /r'  "'^''''"'™  ">  "hi* 'such 

I.»n  r^,,?  ^     ™'*',  ?'  '"""'"''  "Sf"  not  able  to  follow  thn 
hen  about  as  young  chickens  would  have  done,  in  aceordance 

the  np'/fT2      that  this  place  was  not  too  far  away  from 
Yet  T  1^  ?'!r^*  ^''  ^'^"^  ^^^"«g  the  cries  of  dfstresT 

feiS     On  tL    .^      t  ^f 'f  growling  noise  of  a  younc. 
her  bill,  in  the  same  way  as  hens  in  general  comb  out  the 

•  Vol.  xi,  p,  553, 


J  i 


BLENDED  ORIGIN,  OR  PLASTICITY  OF  INSTINCT.         217 

feathers  of  their  chickens.  While  engaged  in  this  process, 
however,  she  used  frequently  to  stop  and  look  with  one  eve 
at  tlie  wriggling  nest-full  with  an  enquiring  gaze  expressive  of 
astonishment.  At  otlxT  times,  also,  her  family  gave  her  good 
reason  to  bo  surprised;  for  she  used  often  to  tiy  off  the  nest 
suddenly  with  a  loud  scream,  an  action  which  was  doubtless 
due  to  the  unaccustomed  sensation  of  being  nipped  by  the 
young  ferrets  m  their  search  for  the  teats.  It  is  further 
worth  while  to  remark  that  the  hen  showed  so  much  uneasi- 
ness of  mind  when  the  ferrets  were  taken  from  her  to  be  fed 
that  at  one  time  I  thought  she  was  going  to  desert  them' 
altogether.  Alter  tliis,  therefore,  the  ferrets  were  always  fed 
m  the  nest,  and  with  this  arrangement  the  hen  was  perfectly 
satisfied— apparently  because  she  thought  that  she  had  some 
share  in  the  feeding  process.  At  any  rate  she  used  to  cluck 
when  she  saw  the  milk  coming,  and  surveyed  the  feeding 
with  evident  satisfaction. 

"  A.ltogether  I  consider  this  a  very  remarkable  case  of  the 
plasticity  of  instinct.  The  hen.  it  should  be  said,  was  a 
young  one,  and  had  never  reared  a  brood  of  chickens  A 
few  months  before  she  reared  the  young  ferrets,  she  had  been 
attacked  and  nearly  killed  by  an  old  ferret  which  had  escaped 
trom  Its  hutch.  The  young  ferrets  were  taken  from  her 
several  days  before  their  eyes  were  open. 

"  In  conclusion,  I  may  add  that  a  few  weeks  before  trying 
this  experiment  with  the  hen,  I  tried  a  similar  one  with  a 
rabbit  which  had  littered  six  days  before  ....  Unlike 
the  hen,  however,  the  doe  perceived  the  imposture  at  once 
and  attacked  the  young  ferret  so  savagely  that  she  broke  two 
ot  Its  legs  before  I  could  remove  it.  To  have  made  the  ex- 
periment parallel  with  the  other,  however,  thp,  two  mammalian 
mothers  should  have  littered  on  the  same  day." 

^in  •^'  turning  to  the  Mammalia,  a  friend  of  the  Rev 
Mr.  White,  of  Selborne,  gave  him  an  account  of  a  leveret 
which  he  saw  reared  by  a  cat.*  Pricliard  gives  an  account 
of  a  cat  that  reared  a  puppy,t  and  from  among  many  analogous 
instances  that  might  be  rendered,  I  shall  only  quote  the 
lollowiug,  as  It  is  remarkable  on  account  of  displaying 
voluntary  adoption  by  a  cat  of  the  young  of  animals  which 
her  other  instmcts  and  constant  practice  had  taught  her  to 
regard  as  prey 

•  Biugley,  Animal  Biography,  i,  269.     f  Nat.  Hist,  of  Mankind,  i,  102. 


:ll 


ir*' 


"T3 


1    'i 


218 


MENTAL  EVOLUTION  IN  ANIMALS. 


'  n 


Te™flerj„no  t  t  1m  =»''vM*™»''"fee  Maxwell  of 
at  the  time  brin"LuB  a  femntS  '''°''  """  "  <«"  ""*  »"« 
weeks  P-viousl|SCtKfTSL^l?f  ""'^ 

young  rats,  and  at  the  time  I  £w  th '^^.^''^  '"°  ™» 
-whichwereconiinedinanemDtvs7»n    „   *^  ''°™S  rats 

the  stable  as  a  particX^goTd  ^^4''^  '''  ""^  ^"^^  » 

•  Mr.  P.  Dudgeon,  2^ature,  vol.  «,  p.  77. 


If '.It 


,  !  ■ 


f       f  1 


R I  ^1 11  { '  !  * 


VARTATION  OF  INSTINCT  IN  DEFINITE  LINES.  219 


CHAPTER  XIV. 

Instinct  (continued). 

Modes  in  which  Intelligence  determines  the  Variation 
OF  Instinct  in  Definite  Lines. 

We  have  now  seen  that  instincts  may  have  what  I  term  a 
blended  origm-or,  m  other  words,  that  intelfigent  adiust- 
ment  by  going  hand  in  hand  with  natural  selection,  iust 
greatly  assist  the  latter  principle  in  the  work  of  forming 
instincts  inasmuch  as  it  supplies  to  natural  selection  varia- 
tions which  are  not  merely  fortuitous,  but  from  the  first 
adaptive.  I  shall  next  show  what  I  conceive  to  be  the  chief 
modes  m  which  intelligence  thus  operates,  or  co-operates 
with  selection,  in  the  formation  of  instincts  ^Peraies 

in  ^l^T-\  \^.f?^"^^'^l  *«^«^s  it  is  easy  to  see  that  the  mode 
m  which  intelligence  thus  co-operates  is  by  enabling  an 
animal  to  perceive  that,  owing  probably  to  some  change  in 

Sh-nr'T^T^-?  T^?''^  ^^^P<^  ^^««^f  ^°  the  existing^on- 
ditions  of  Its  hfe  by  deviating  in  some  degree  from  its 
ancestral  instincts  (as  when  the  tailor-bird  seeks  for  threads 
ot  cotton  instead  of  fibres  of  gr.ss  wherewith  to  sew  its  nest) 

whtVhv  '"'""^'^''^'^^^  S^^^"^  '''^  *^  ^'^J^^tive  action  ; 
r«i  f  I  '^^P^t^tio"  lead  to  an  instinct  de  novo  (as  in  the 
TJS  f  ^°"^y:g"^^f'  ^hich  has  acquired  the  remarkable 
instinc.  of  attracting  the  attention  of  man,  and  leading  him 
t..  -he  nests  of  bees).*  But  with  animals,  as  with  men 
oi^gmal  Ideas  are  not  always  forthcoming  at  the  time  they 
a,  e  wanted,  and  therefore  it  is  often  easier  to  imitate  than 

whereby  mteigence  may  change  or  deflect  an  instinct,  is 

that  of  imitation.     For  although  it  is  true  that  the  iniiial 

stage  ol  such  deflection  occurs  in  the  "  original  ideas,"  nothing 

•  See  Animal  Intelligence,  p.  315. 


i  «n  'i 


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II, 


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220 


MENTAL  EVOLUTION  IN  ANIMALS. 


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further  remains  to  be  said  of  these.  If  they  occur  similarlv 
and  simultaneously  in  a  large  number  of  ind^ivTduds  Ts  may 
be  the  case  where  the  new  adjustment  is  simple  and  obviouT 

nstTncT^  vr  "'??  '^  ^°^^'"^^°^  *^  ^'^'^'^^  changing  the 

SS;  m  ;''  °^^''  '^'''  ^  ^"^  ^^^li^^d  to  thi^k  that 
mutation  may  play  an  important  part  in  this  matter.  I  must 
confess,  however,  that  in  searching  for  evidence  of  one  sS 
of  animal  imitating  the  beneficial  habits  of  another,  fhave 
been  surprised  at  the  rarity  of  its  occurrence,  although  as  I 
shall  present  y  show,  there  is  abundant  eWdence  of  one 
^nd^v^dual  imitating  the  habits  of  another  individua^-whethe? 
of  Its  own  or  of  other  species,  and  whether  the  action  imitated 
IS  beneficia  or  useless.     This  difference,  I  think  is  nrobablv 

Lta'tirV'r '  '^ '"'  ''""'''r  ^^^^^  '^  '"^  -"-  iCe:nl 

imitation  between  species  and  spocies  may  have  obtained  in 
the  past,  we  should  now  only  see  an  instinct  common  to  the 
two  species,  and  therefore  should  have  no  evidence  that  it 
was  not  always  common.  Consequently,  it  is  only  in  cases 
where  the  imitation  by  one  specie!  of  ti'e  habits  oVanoth 
IS  in  It   earher  phases  that  we  can  find  evidence  of  the  fact 

W  f  'm^  r  *^'  ^"^^  '''''  «f  «^^h  i^-^^itation  that  I 
have  been  able  to  meet  with;  but  to  them  I  add  a  number 
of  cases  of  individual  imitation,  because  this  must  evidS 
form  the  groundwork  of  imitation  among  species  ^'''^''^^^ 
1  quote  the  following  from  Mr.  Darwin's  MSS  •- 
J^rom  some  experiments  which  I  was  making  I  had 

bean  Tn  J7/T^^  ''  ^"'^^  ^^^^  ^^^«  °^  '^'  tall  Mne^- 
bean  and  I  daily  saw  innumerable  hive-bees  alightina  as 
usual  on  the  left  wing-petel,  and  sucking  at  the  moSth  of  the 
flower  One  morning,  for  the  first  time,  I  saw  several 
humble-bees  (which  had  been  extraordinarily  rare  aTsummer 
w^hTb.'^'''  ^\T'  1^1  ^  «"^  *^^^  i^  the  act  of  cXng 

Svx  and'  tZ^        f-  ^°ll'  '^^''"^^  '^'  "^^^^  '^^'  «f  the 
calyx,  and  thus  sucking  the  nectar:  all  the  flowers  in  the 

course  of  the  day  became  perforated,  and  the  hur^ble-bees  in 

heir  repeated  visits  to  the  flowers  were  thusTaved  mucS 

beef  tjfhonf  r^-    .^^'  ""'^  "^"^  ^^y  I  ^-"d  ^11  theCe. 
bees    without  exception,  sucking  through   the  holes  which 

had  been  made  by  the  humble-bles.     hSw  did  the  hive  bees 

find  out  that  all  the  flowers  were  bored,  and  how  didThev  'o 

suddenly  acquire  the  habit  of  using  the  holes  ?    I  never  saw 

though  I  have  long  attended  to  th?  subject,  or  heard  of  W 


TARUTION  OF  INSTINCT  IN  DEFINITE  LINES.  221 

bees  themselves  boring  holes.     The  minute  holes  made  by 
the  humble-bees  were   not  visible  from  the  mouth  of  the 
flower,  where  the  hive-bees  had  hitherto  invariably  alighted 
nor  do  I  beheve,  from  some  experiments  which  I  h^ave  made 

of  thf  flower      Th!\T'  r^^^  ^Y""  ^^''""^^  ^^^  ^^^^^ 
^hinV^W  ft    T,-     l  ^^^"ey-bean  is  also  an  exotic.     I  must 

hP  Ll.f  ^  ^'1'^'''  f^^''  '^^  *^^  humble-bees  cuttin  ' 
the  holes,  and  understood  what  they  were  doin-  and  imme- 
diately  profited  by  their  labour ;  or  that  they  merely  imSd 
the  humble-bees  after  they  had  cut  the  holes.  anT  when 
sucking  at  them.  Yet  I  feel  sure  that  if  anyone  who  had 
not  known  this  previous  history  had  seen  every  single  hive- 
bee,  without  a  moment's  hesitation,  flying  with  the"  utmost 
celerity  and  precision  from  the  under  side  of  one  flower  to 

Zl    '"i  ffV-^^  '"P^^^^  '""'^^'S  the  nectar,  he  wouW  have 
declared  that  it  was  a  beautiful  cSse  of  instinct » 

Mr.  Darwin  in  his  MSS  has  also  the  following,  observa- 
tions concerning  the  subject  of  imitation .— "  ItTs  difficult  to 
determine  how  much  dogs  learn  by  experience  and  Sion 
I  apprehend  there  can  be  little  doubt  that  the  manner  of 

occ,  tom.  IV  p.  d39).  I  believe  that  certain  doc^s  in  South 
America  without  education  rush  at  the  belly  Sf  the  s  a^ 
which  they  hunt,  and  that  certain  other  do^s  when  fi^st 
taken  out  run  round  the  heads  of  Peccaris.     We  are  led  to 

S?7M>t  ^?T/^'"^^  '''  '"^^'^^  when  we  h ear  f^om 
Sir  J.  Mitchell  ('Australia,'  vol.  i.  p.  292),  that  his  dogs  dS 
not  learn  how  safely  to  seize  the  Emu  by  the  neck,  untU  the 
close  of  his  second  expedition.  On  the  other  hand  Mr  Couch 
(Illustrations  of  Instinct,'  p.  191)  gives  the  case  of  a  dS 
who  learned,  after  a  single  battle  with  a  Bad'er  ?he  spot 

lesson       In  the  Falkland  Islands  it  seems  that  the  do^^s 

iaXlc^''?'  P ''^  ."^^'^  '^'  ^'''  w^y  «f  -tt^^king  the  wild 
cattle  (Sir  J.  Eoss,  '  Voyage,'  vol.  ii,  p.  246)." 

Again,  Mr  Darwin  points  out  that  many  species  of  wild 
animals  certainly  learn  to  understand  and  to  profit  by  the 
danger  cries  and  signals  employed  by  other  species,  and^his 
18  a  kind  of  imitation.*     He  also  adduces  a  good  deal  of 


■ill 
1 


H. 


: '  t 


:i*!    n 


Hi  Hi     'i 


■■'!■ 


i  ; 


i  ! 


222 


MENTAL  EVOLUTION  IN  ANIMALS. 


evidence  to  show  that  birds  of  different  species,  whether  iu  a 
state  of  nature  or  domestication,  frequently  imitate  one 
another s  song;  and  singing  is  certainly  instinctive,  for 
Couch  says  that  he  knew  a  gold-linch,  which  had  never 
heard  the  song  of  its  own  species,  nevertheless  singing  tliis 
song,  though  tentatively  and  imperfectly  * 

YaiTell  tells  of  a  hawfinch  that  learnt  the  song  of  a 
blackbird,  though  afterwards  it  quite  forgot  this  son^ 
which  could  not  have  happened  with  its  natural  musio.tt 
tact  which  shows  that  although  imitation  is  able  largely  to 
modify  instinct,  its  effects  are  not  so  deeply  engrained  as 
those  which  are  stamped  by  heredity.  Even  the  sparrow 
which  naturally  can  scarcely  be  said  to  have  a  soncr  will 
learn  the  song  of  a  linnet,?  and  Bureau  de  la  Malle  gives  the 
case  of  wild  blackbirds  in  his  garden  learning  a  tune  from  a 
caged  bird  ;§  similarly,  he  taught  a  starling  the  Marseillaise, 
and  from  this  bird  all  the  other  starlings  in  a  canton  to  which 
he  took  it  learned  the  air.  In  this  way,  too,  many  birds 
acquire  the  song  of  their  foster-parents  of  other  species  || 
Lastly,  a  number  of  observations  on  wild  birds  in  America 
imitating  each  other's  music  have  lately  been  published  bv 
Mr.  E.  E.  rish.f  ^  ^ 

It  is  certain,  however,  that  some  birds  have  a  much 
greater  aptitude  than  others,  both  for  learning  and  retainincr 
the  songs  of  different  species.  Thus  a  blackiaird  [starling  r\ 
has  been  known  so  well  to  imitate  the  crowing  of  a  cock  as 
to  deceive  the  cocks  themselves,**  wliile  Yarrell  says  the  same 
thing  ot  a  starlmg's  power  of  imitating  the  cackling  of  a  hen  ft 
u-  /°/T^  ^^^^  ^^^^^  ^^®  notorious  as  regards  the  Mocking- 
bird {Turdus  polyglottus),  and  also,  at  least  when  in  a  state 

appears  serves  to  alarm  the  chickene,  though  the  latter  are  not  aborigines 

ot  the  country."    And  many  similar  instances  might  be  given. 

4th  edp!??^'""*  o/7«*««c#,  p.  113.      See  also  Bechstein,   Stulenvogel, 

t  Brit  Birds  vol.  i,  p.  486.  J  Descent  of  Man,  p.  370. 

§  Anns,  des  Sc.  Nat.,  3rd  series.     2  vol.     Tome  x,  p.  118       '^     '  ' 

II  Barnngton,  Phil.  Trans.,  1773,  p.  264 
J  Bulletin  of  the  Buffalo  Society  of  Nat.  Sc.     1881,  pp.  23-6. 
•*  Loundoun's  Mag.  Nat.  Hist.,  vol.  iv,  p.  433 

«n;!/«^f^'  "^  V*"-:  '■  ^.-  "°^'  ''^'°.  *"  ^^^  ^'^■'  ^0'"  "'  PP-  229-30,  where  it  is 
said  on  the  authority  ot  sundry  observers,  that  starlings  in  a  state  of  nature 

;lwrnwJ^'^rt"'^r''^'  Pf^*"^^'''  °^°°^^*''    coot,  oyster-catcher! 
golden  plover,  redshank,  curlew,  whimbrel,  herring-gull,  quail,  and  corn 
crake,  while  Professor  Newton  tells  me  that  at  Cambridge  he  ha    heard  tli« 
Btarbngs  very  perfectly  imitating  the  quacking  of  ducks. 


VAEIATION  OF  INSTINCT  IN  DEFINITE  LINES  223 

and  that  very  freoupuHv  «il  iw  T  ■  I  ^^^  performance, 
in(T  OnZh  .f^^l^^^y  ^^  instruction  is  forgotten  in  raoult- 
^L  f ?        '  '"-^^^^i  '^^^  <^^a<^  with  all  such  birds  "  it  k 

dulness  to  require  nine  mnnf-h^  of  1!?  ,-       ^-    ^^  unusual 

of  the  powe'TvtTta^  ion  ;S  thrS'^  2*™" 
unquestionably  that  of  uttering  articulate  wor,)^  ^  X'' 
subject  will  require  to  be  considered  mo^  ft,  IW'  ^'"' 

utterinof  a  caw  or  sorpam  info  fv,^    y-i^^^^^o  tne  instinct  of 
or  the  a°peaking?f  SSte"  ""=""»"  °'  ^  '^""'"^  '™« 

washfng'thefr  fSZil'^lt'^H'  'T-  ^°™S  "'i"™'-  "f 
most  p?ob„bly  Tt  isT  ta  That  tttTf/"^"^"™'.'"'"'  '"■ 
imitation  is  proved  bV  the  WfW    ^  •"^°  ^  "<=1»'''«<'  by 

by  a  cat  perf^^l'^Lt'tleSr^This'™'"'"'/? 
observed  by  Audouin  *  «nH  >,ol     •        [  "^^   ^"^   ^^'st 

corroborated  byseyml  observers?/' ^'%^"^^^P^^^^"^^3^ 
the  following:-  observers,  of  whom  I  may  mention 

Bureau  de  la  Malle  gives   the  case  nf  n  fn.  •        u-  i. 
belonged  to  himself,  and'which  fU  the  ti  JT?f  A^'Jk 

.•s.teir2  :.'=.=— '5£:-S 

•  Anns,  des  So.  Nat,  torn,  xxii,  p.  397. 


-Ij 


'I  P  WJtH 


•I 


*  .if 


•lit 


^^^K: 


224 


|i:  : .,' 


!■• 


. 


.!•    i 


MENTAL  EVOLUTION  IN  ANIMALS. 


f  V.1  w  >K^"  *?  ^^^"'^  ^'^"  ^  ^''^*'  ^^d  ^^  ^0"  a  mouse  or 
rnS  fT  ^  ^''  ^ove-V^^ys ;  he  also  Kcked  his  paws  and 
rubbed  them  over  his  ears.     Yet  if  a  strange  cat  came  into 

of?dn^?  ^",'^r^  ''  T"^-*  ^''''^'^'^  Si^^'  -"°ther  case 
,/.  itA  T^  ^^  ^  T^  '^'"^°S  ^°  ^^«k  its  paws  and  wash 
bv  MrAf  /^'""'"'^f  "'\^^'  ''^'^  ^'  communicated  to  me 
.1  /  ;i  •  6  1^'"^':  .Another  precisely  similar  case  I  find 
recorded  m  Mr.  Darwin's  MSS  as  -rT,„ipr,,-..,.f^d  to  him  bv 
Professor  Hoffmann  of  Giessen.     ...    :   ,  the  late  DrXit{ 


President  of  Magdalen  College, 


L 


observed  that   his 


tt;,  n\  1  r  °: — y  ,  Y""^o'='  '-  '  ^.  uoservea  tnat  his 
King  Charles  terrier  (which  had  been  suckled  and  reared  by 
a  cat  from  the  age  of  three  days)  was  as  afraid  of  rain  as  wal 

avoid  it  set  his  paw  m  a  wet  place  ;  that  he  licked  his  feet 
two  or  three  times  a  day  for  the  purpose  of  washing  his  face 
which  process  he  performed  "in  the  true  ca  d^Tpo  iUon 
sitting  upon  his  tail;"  that  "he  used  to  watch  a  moS  ole 
for  hours  together;"  and  had  "in  short  all  the  wayf  manners 
and  dispositions  of  his  wet-nurse."i    Lastly,  anot  encase  Ts 
recorded  m"  Nature  "§  of  a  dog  belonging  to^Mr.  0  H  Jeens 
which    having  been  reared  by  a  caf  from  the  age  of  one 

It  after  the  well-known  manner  of  cats,  allowing  it  to  run  a 
distance  then  pouncing  upon  it,  and  so  on  for  maSy  minutes  " 

?Zr:f^  S'-'^-  ?'-^'T  ''''''^'  *'^^  ^^«^  o^  a  cat  learn L 
from  a  dog  the  medicinal  use  of  the  herb  Agrostis  canina     I 

think  It  IS  probable  that  the  following  factlwhicn  quote 

IZJpd  ?'•"'' w-^^!'  ''I  '^'''  '^  P^^t'at  least  tHe 
attributed  to  imitation,  though  here  the  imitation  is  within 
the  limits  of  the  same  species.  witxiiu 

"It  has  been  stated  that  lambs  turned  out  without  their 
mothers  are  very  liable  to  eat  poisonous  herbs  ;  ai7drt  seams  to 
be  certain  that  cattle,  when  first  introduced  into  a  countrT  a  e 
killed  by  ea  mg  poisonous  herbs  which  the  cattirSadv 
naturalized  there  have  learnt  to  avoid  "(|  ^ 

It  seems  needless  to  give  further  instances  of  imitation 

•  Anns,  des  Sc.  Nat.,  torn,  xxii,  p.  388 

t  ^'?'-  EH-  ''/■^««*'»'^,  3rd  ed.,  vol.  i,  p.  102 

I  Miss  Mitford's  Life  and  Letters,  vol.  u,y.  277 
§  Nature,  vol.  viii,  p.  79.  ^ 

II  See  Annls,  and  Mag.  of  Nat    m»*     9„,i  o„-        i    •• 

Stillinpjleet'a  Tracts,  p.  350.     I„  reef  d   tn  T      k  "  ''°'\^''  P"  ^^^'  «°d 
p.  40*.  '  ^  -^^  '^e^^"^  ^°  ^''"ibs,  see  Youatt  on  &heep, 


M' 


VARIATION  OF  INSTINCT  IN  DEFINITE  LINES.  225 

among  animals,  but  it  may  be  said  in  general  thaf  o.  iJ.. 
faculty  of  imitation  depends  on  observation  if  \.f      i  ^^ 

fl-i^   u    '  <^o^'nection  it  is  interesting  to    observe Tw' 
a  child  begins   to  imitate  very  early  in  life  and  Xf  .^ 

vatbnfo;  tSSieli^eT^tS^^^^  o^  detailed  obser- 

as  early  as  the  fifteenthweek  SSSn  .5  '^''"'*^^'''^ '""^*^™«"^  begins 
this  action  before  the  child  rThi^acS^ll/.^'P'  ^^'"  '^"y^""  P^^f«™« 
children,  and  may  1  think  urobablv  bfj!!  T  *°,''°'°^  naturally  to  young 
same  movement  a^s  sotSglT^rimZ^^^  «ith  thf 

of  such  protrusion  in  this  aniLT  see  Dar-'n  ^  °^  ""l^'^^"  ^^'^  ^  ?'«*"••« 
Towards  the  end  of  tlie  first  ^ar  i^ff  f •         ^^P^^^^^on  of  Emotions,  p  Hl.T 

and  more  quickly  le't  and  Se  cMd  tXT^J^'"?'  ^''^'""^  "^''^  ""-'«'•«" 
ance.     At  twelve  mouths  P?evS^oh«.  11^  l^^  ^°  **iei''  pertbrm- 

imitative  movements  ShaKaristron'  ^^^^^  ^-^P'^'^ti^g  in  its  dreams 
-e.g.,  blowing  with  the  mouth  Tatr  stll  com^flTT'^  ^^  ''  ^'^''^  '^-'^ke, 
are  performed  for  mere  amusement  ««  fa  a^P!*^^^  "niitative  movements 

t  With  reference  to  SSn  'in       ^PPf «"'!.!  t^^^  case  with  monkeys, 
desirable  here  again  to  exnreir.  "^.''?""«f «° '^'tli  instinct,  I  think  it  is 

thatthenidificationVbirdsis  due  5^  fbY  '''  v  >  ^«^"^«^  '^«'^''^'««. 
the  structure  of  the  nests  Tn  which  ?hev  hav«T^  \  '''^'^f  ""^^^  i'^if «ting 
characteristic  nidification  of  eS  species  of  bird  ?''^'f^  been  reared-the 
have  advanced  in  Animal  InteuL2tlT ^  H^'°^  *^"^  maintained.     I 

thought  sufficient  to  StiveS  considerations,  which  I 

I  have  found  auiong  S  Slrw,Vs  MSsV'f  ir'l^^''''^'  '  ^"'^  «i°««  then 
of  the  test  experiment  whk.hSrWantehtflf''^''*'  f''t^''  '^'  ^««"it« 
"  to  rear  young  birds  from  the  ^7^  an  ScJ^V'"-   ."f  ^i^-Periment 

"o  «3gg  m  an  artibcial  nest  or  incubator  unlika 


I 


i 


:H    'f 


;  'I- 


226 


MENTAL  EVOLUTION  IN  ANIMALS. 


Ir^l  '! 


But  the  influence  of  this  faculty  in  the  formation  of 
instinct  proceeds  further  than  we  have  yet  noted.  For 
among  the  more  intelligent  animals  it  is  played  upon  for  this 
very  purpose  by  the  animals  themselves ;  the  parents  of  each 
successive  generation  intentionally  educate  their  young  in 
the  performance  of  quasi-instinctive  actions.  Thus,  for 
instance,  old  hawks  purposely  educate  the  instinctive  facul- 
ties of  their  young,  so  as  more  quickly  to  bring  these  instincts 
into  a  state  of  perfection.  For  the  manner  in  which  hawks 
swoop  upon  their  prey  must  certainly  be  regarded  as  instinc- 
tive ;  yet  La  Malle  observed,*  and  the  observation  was  after- 
wards corroborated  by  Brehm,t  that  the  old  birds  perfected 
the  natural  instincts  of  their  young  ones  in  teaching  them 
"dexterity,  as  well  as  judgment  of  distances,  by  first  dropping 
through  the  air  dead  mice  and  sparrows,  which  the  young 
generally  failed  to  catch,  and  then  bringing  them  live  birds 
and  letting  them  loose."t 

And  analogous  facts  are  to  be  observed  in  the  case  of  old 
birds  teaching  the  young  ones  to  fly.  We  have  already  seen 
that  Mr.  Spalding  proved  such  teaching  to  be  unnecessary  in 
the  sense  of  not  being  required  to  develop  the  power  of  flight. 
This  is  instinctive,  so  that  the  young  bird,  whether  or  not 
instructed  by  its  parents,  would  fly.  Yet  the  instruction 
must  be  of  some  use,  as  in  some  species,  at  any  rate,  it  is 

the  natural  nest,  and  then  observe  whether  when  adult  these  birds  will 
InstinctiTely  build  the  nest  characteristic  of  their  species.  Now  I  find 
among  Mr.  Darwin's  MSS  a  letter  to  him  from  Mr.  Weir,  which  seems  to  set 
any  such  question  at  rest.  Writing  under  the  date  May,  1868,  Mr.  Weir 
says  as  the  result  of  a  large  experience  of  birds  kept  by  Lim  in  aviaries  : — 
"  The  more  I  reflect  on  Mr.  Wallace's  theory  that  birds  learn  to  make  their 
nests  because  they  have  been  themselves  reared  in  one,  the  less  inclined  do  I 
feel  to  agree  with  him."  He  gives  the  following  fact,  which  seems  to  be  con- 
clusive against  this  theory : — "  It  is  usual  with  many  Canary  fanciers  to  take 
out  the  nest  constructed  by  the  parent  birds,  and  to  place  a  felt  nest  in  its 
place,  and  when  the  young  are  hatched  and  old  enough  to  be  handled,  to 
place  a  second  clean  nest,  also  of  felt,  in  the  box,  removing  the  other,  and  this 
is  done  to  avoid  acari.  But  I  never  knew  that  canaries  so  reared  failed  to 
make  a  nest  when  the  breeding  time  arrived.  I  have  on  the  other  hand 
marvelled  to  see  how  like  a  wild  bird  their  nests  are  constructed.  It  is  cus- 
tomary to  supply  them  with  a  small  set  of  materials,  such  as  moss  and  hair  ; 
they  use  the  moss  for  the  foundation,  and  line  with  the  finer  materials,  just 
as  a  wild  goldfinch  would  do,  although,  making  it  in  a  box,  the  hair  alone 
would  be  sufficient  for  the  purpose.  I  feel  convinced  nest  building  is  a  true 
instinct." 

•  Anns,  de  Sc.  Nat.,  torn,  xxii,  p.  406b 

t  Maff.  Nat.  Hist.,  vol.  ii,  p.  403. 

X  Descent  of  Man,  p.  73. 


fci,  I  ' 


Hf 


VARIATION  OP  INSTINCT  IN  DEFINITE  LINES.  227 

laborioualy  given ;  *  and  the  only  use  it  can  be  is  that  of 
developing  the  powers  of  flight  more  rapidly  than  they 
would  develop  if  not  thus  assisted. 

Similarly,  the  singing  of  birds  is  certainly  instinctive; 
yet  It  IS  improved  by  imitation  and  practice— the  younc* 
birds  listening  to  the  old  and  profiting  by  their  instruction^' 
as  IS  proved  by  the  cases  previously  cited  of  birds  which  liad 
never  heard  the  songs  of  their  own  species  yet  singino-  their 
songs,  but  doing  so  "  tentatively  and  imperfectly."  ""  ° 
^  Again,  although  terriers  take  to  hunting  rabbits  instinc- 
tively, it  is  usual,  as  I  have  myself  observed,  for  their 
parents  to  teach  them,  or  lead  on  their  natural  instincts  by 
imitation,  whereby  the  hereditary  aptitude  develops  more 
quickly  than  it  would  if  left  to  itself. 

The  Duke  of  Argyllf  give  a  curious  case,  which  he  "knows 
to  be  authentic,"  of  a  golden  eagle  in  the  possession  of  Mr. 
W.  Pike,  Glendarry,  Co.  Mayo,  which  in  the  spring  of  1877 
laid  three  eggs.  These  Mr.  Pike  took  away,  and  substituted 
for  them  two  goose  eggs.  The  eagle  hatched  out  the  two 
eggs.  One  of  the  goslings  died,  and  was  torn  up  by  the 
eagle  to  feed  the  survivor,  "  who,  to  the  gi-eat  tribulation  of 
Its  foster-parent,  refused  to  touch  it.  .  .  .  The  eagle, 
however,  in  the  course  of  time,  taught  the  goose  to  eat  flesh^ 
and  (the  goose  having  free  exit  and  ingress  to  the  eagle's 
cage)  always  called  it  by  a  sharp  bark  whenever  flesh  is 
given  to  it,  when  the  goose  hastens  to  the  cage,  and  greedily 
swallows  all  the  flesh,  &c.,  which  the  eagle  gives  it." 

Again,  there  is  evidence  to  show  that  the  knowledge 
which  animals  display  of  poisonous  herbs  is  of  the  nature  of 
a  mixed  instincfe,  due  to  intelligent  observation,  imitation, 
natural  selection,  and  transmission ;  for,  as  Mr.  Darwin  points 
out  in  the  Appendix,  "lambs  turned  out  without  their 
mothers  are  very  liable  to  eat  poisonous  herbs ;  and  it  seems 
to  be  certain  that  cattle,  when  first  introduced  into  a  country, 
are  killed  by  eating  poisonous  herbs,  which  the  cattle  already 
introduced  have  learnt  to  avoid."| 

In  this  case  there  is  indeed  no  evidence  of  the  young 

.  *  ^"^:  -^"^^y  g^^®8  ^°  account  of  such  laborious  instruction  as  witnessed 
by  hirnself  m  the  case  of  the  golden  eagle.     See  Animal  Intelliqence,  d  290 

t  Nature,  vol.  xix,  p.  554.  ;,     .  ,  v     <>  . 

J  Youatt  on,  Sheep,  p.  404.  j  and  dnnt.  and  Mag.  Hat.  HUt.  2nd  apt. 
vol.  u,  p.  364,  &c.  ' 


,  \  \  1.1 


nil    ill 


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1:1 


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228 


MENTAL  EVOLUTION  IN  ANIMALS. 


being  intentionally  instructed  by  the  old,  but  they  are  in- 
structed by  themselves,  i.e.,  by  their  individual  experience. 
And  this  18,  after  all,  the  most  important  point,  or  the  point 
to  which  the  intentional  education  by  parents  is  subsidiary. 
1  shall  therefore  give  a  few  more  instances  to  show  that 
many  instincts  (usually  those  of  obviously  secondary  origin) 
are  first  manifested  by  young  animals  in  an  imperfect,  or  not 
luHy  evolved  condition,  and  afterwards  become  perfected  in 
the  school  of  individual  experience.  Such  cases  stand  in 
marked  antithesis  to  those  of  the  congenitally  perfect 
instincts  already  alluded  to,  which  have  been  so  weU  investi- 
gated by  Mr.  Spalding. 

It  is  unquestionably  a  true  instinct  that  leads  a  ferret  to 
thrust  Its  long  canines  tiirough  the  medulla  oblongata  of  its 
victim ;  but  Professor  Buchanan  states*  that  youn^r  ferrets 
•;  instead  of  having  for  their  single  object  to  put  themselves 
into  a  position  to  inflict  the  death  wound,  engage  in  conflict 
with  rats  ;"  yet  they  had  the  proper  instinct,  though  not  in 
complete  working  order,   for  they  attacked    properly  the 
medulla  oblongata  of  dead  rats.     Similarly  I  myself  observed 
with  the  ferrets  which  I  reared  under  a  hen,  that  when  half- 
grown  and  put  to  a  rabbit  for  the  first  time,  they  clearly 
knew  that  their  attack  should  be  directed  against  one  end  of 
the  rabbit,  but  were  not  quite  certain  which ;  for  after  some 
time  of  indecision  they  in  the  first  instance  attacked  the 
rump,  and  only  after  finding  this  of  no  use  tried  the  proper 
place.     But  of  more  interest  stiU  in  this  connection  was  the 
behaviour  of  these  ferrets  when  half-grown  towards  a  fowl. 
They  had  been  taken  away  from  their  foster-mother  the 
hen    some  weeks  previously,  but  still  no  doubt  retained  a 
recoUection  of  her.     Therefore,  when  presented  with  another 
hen,  their  hereditary  instincts  prompted  attack,  while  their 
individual  associations  inhibited  the  prompting.     There  was 
therefore  a  manifest  conflict  of  feelings,  which  had  its  ex- 
pression in  a  prolonged  period  of  indecision.     And  although 
eventually  the  hereditary  instincts  prevailed  over  the  ass*o- 
ciations  formed   by  individual    experience,  the   prolonged 
hesitation  proved  that  the  latter  exerted  a  strong  modifvinrr 
force.  °  "^    ° 

Mr.  Darwin  says  in  his  MSS  that  in  1840  he  saw  some 
chickens  which  had   been  hatched  without  a  mother,  and 

•  Anns,  and  Mag.  Nat.  Hist.,  vol.  xviii,  p.  3/8. 


^  VARIATION  OP  INSTINCT  IN  DEFINITE  LINES.  22D 

"when  exactly  four  hours  old  thev  ran    iumnpri    .\.w     i 
scratched  the  ground,  and  cuddledTogTtt  r^  ^M 
hen ;  aU  actions  beautifully  instinctive."    After  Jvint  tin-! 
as  an  instance  of  what  I  have  called  pure  i  istinct  1^  no 
ceeds  by  way  of  comparison  to  say    "It  m    1 1  hnvl  y 
thought  that  the  man'ner  in  whicY' fowls  Sk  rfilW- 
their  beaks  lifting  up  their  heads,  and  aUowin-.  the  water  to 
rundown  by  Its  gravity,  would  have  been  sp'^eciallHau  .ht 

asL'dThat'  tl  T^  "°'.  ^\^^^  ^  "-  nS  Sly 
assured  that  the  chickens  of  a  brood  reared  by  themselves 

C'ff  IL'T^^'^  'Vr  ^^!^«  t«  be  pressed  ini  a  Troth 
but  If  there  were  older  chickens  present,  who  had  learnt  to 

at^;efth^;arr  ^"^^  ^^^^^^^  ^^^^^  -vements^  Ind  tU^ 

^\1T^'  i^V^bole.   then,  with  reference  to  the  modes 

s?y  tha^  ?n  Sfr'  ^P^J^^^l^^^o^ifying  instinct,  we  ma^ 
say  that  m  aU  cases  when  it  does  so,  there  must  first  be 
mtelligent  perception  of  the  desirability  of  the  modification 

ac'c  rdiS  ^r.ot  "''"^^^'  "^°  -°^^^>  ^^:^z 

accordingly  In  some  cases  the  principle  of  imitation  nro- 
bably  assis  s  in  changing  the  instinct  by  inducing  other  indi- 
viduals of  the  same  species,  and  living  in  the  same  area  to 
follow  the  example  of  their  more  intelhgent  commnions    or 

the  hab  ts  of  one  species  sngyestinff  to  the  members  of  anothe; 
species  the  modification  of  an  instinct.  Lastly,  nteSnce 
m^y^operate  by  the  intentional  tuition  of  yo^uufby  fhei? 

T.T,,-^T."*'-^T-^T  *^^  ^^^^  evidence  of  the  extreme  modification 
which  instinct  maybe  made  to  undergo  by  the  effects  of 
individual  experience,  or  of  changed  conditio^  (^^^  li?e  islhat 
which  IS  afforded  by  the  enormou^s  mass  of  facts   o  wh  ch  we 
are  naturally  led  on  by  some  of  the  cases  just  given  •  I  mein 
the  tos  connected  with  the  domesticatioi  of  linimds  Tor 
the  effects  of  domestication  in  modifying  instincts  are  miZ 
as  strongly  shown  as  are  its  effects  in^nodi'^^^^glt"^^^^^^^^^^ 
as  was  long  ago  observed  by  Dr.  E.  Darwin.^  So  important 
and  extensive  a  class  of  facts,  however,  require  toTe  con- 
sidered  by  themselves.     I  shall  therefore  now  proceed  to  do 

mitation  or  of  education  operating  upon  instinct  durina  the 
lifetime  of  tlie  individual.  ^^i-m^  tue 


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230 


MENTAL  EVOLUTION  IN  ANIMALS. 


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(■■ 


\  \  ■■ 


CHAPTER  XV. 

Instinct  (continued^ 

Domestication. 

Fkom  the  nature  of  the  case  it  is  not  to  be  expected  that  wo 
should    obtain  a  great  variety  of   instances    among  wild 
animals  of  new  instincts  acquired  under  human  observation 
seemg  that  the   conditions  of  their  life   as   a  rule  remain 
pretty  uniform  for  any  periods  over  which  human  observa- 
tion can  extend.   But  fortunately,  from  a  time  anterior  to  the 
beginning  of  history,  mankind,  in  the  practice  of  domestica- 
ting animals,  has  been  engaged  on  making  what  we  may 
consider  a  gigantic  experiment  on  this  subject.     Seeing  that 
the  animals  chosen  for  this   purpose  have  been  bred  and 
reared  under  human  care  for  a  series  of  innumerable  genera- 
tions, and  that  in    some    cases  the    members  of   certain 
"  breeds "  are  persistently  selected  and  trained  to  perform 
certain  kinds  of  work,  we  should  expect,  if  instincts  arise  by 
secondary  means    in    conjunction  with    primary,    to    find 
evidence,  not  only  of  the  dwindling  of  natural  instincts,  but 
also  ol  the  formation  of  new  and  special  instincts.    For  it 
IS  evident  that  artificial  education  and  artificial  selection  by 
man  are  influences  the  same  in  kind,  though  not  in  degree,  as 
those  of  natural  education  and  natural  selection,  to  the  com- 
bined operation  of  which  our  theory  ascribes  the  formation  of 
instincts.     We  might  therefore,  as  I  have  said,  expect  to  find 
among  our  domestic  animals  some  evidence  of  the  formation 
of  what  we  may  call  artificial,  or  in  Mr.  Darwin's  phraseology 
domestic  instincts.     And  such  evidence  we  do  find. 
_     Taking  first  the  case  of  the  impairment  or  loss  of  natural 
instincts,  I  have  already  alluded  to  the  striking  example 
supplied  by  the  hereditary  tameness  of  domesticated  animals. 
More,  however,  now  remains  to  be  said  on  this  point,  foi  it 


Hi 


DOMESTICATION. 


S81 


will  be  rememberod  that  previously  our  attention  wag  con- 
fiiiod  to  ciistis  in  which  this  loss  is  to  be  attributed  to  changed 
experience  rdone,  without  the  aid  of  selection,  or  to  primary 
means  unassisted  by  secondary.  In  this  connection  I  ad- 
duced the  cases  of  the  Rabbit  and  the  Duck ;  I  shall  now 
adduce  the  cases  in  which  artificial  selection  has  probably- 
assisted  mere  disuse  in  obliterating  natural  wildness. 

The  most  remarkable  of  these  instances  is  perhaps  that 
supplied  by  the  Cat,  inasmuch  as  the  nearest  congener  of 
this  animal— the  wild  cat— is  the  most  obstinately  untame- 
aljle  of  all  animals.     The  case  of  the  Dog,  however,  is  in  this 
connection  scarcely  less  remarkable,  seeing   that  fierceness 
and  distrust  are  such  constant  features  in  the  psychology  of 
all  the  wild  races.     Probably,  too,  if  there  were  such  an 
animal  now  in  existence  as  the  truly  wild  Horse,  we  should 
find  Its  disposition  to  resemble  that  of  the  Zebra,  Quagga,  or 
Wild  Ass,  the  latter  of  which,  though  not  so  untractaTle  as 
either  of  the  former,  is  nevertheless  a  very  different  animal 
in  this  respect  from  our  proverbially  patient  donkey.     Simi- 
larly, as  Handcock  observes,  "  In  the  wild  state  kine  possess 
acuteness  of  sight  and  smell,  and  a  spirit  of  fierceness  in 
defending  their  young,  which  disappear  when,  by  domestica- 
tion, we  have  reduced  them  to  a  condition  in  which  the 
former  of  these  qualities  would  be  of  no  value,  and  the  latter 
dangerous  to  themselves  and  others."    This    consideration 
led  Handcock  to  add  the  shrewd  remark,  "  Upon  the  whole 
it  seems  to  be  established  as  a  principle  that,  where  there 
is  no  room  for  the  exercise  of  pure  instinct,  either  by  man's 
interposition    or  otherwise,  it  will  languish,  like  all  the 
natural  senses."* 

So  much,  then,  to  prove  that  instinctive  wildness  is 
eradicated  from  all  species  which  have  been  sufficiently  Ion" 
exposed  to  tlie  influences  of  domestication.  I  shall  now  give 
a  few  facts  to  show  that  the  power  of  domestication  thus  to 
reduce  or  destroy  the  innate  tendencies  of  w^ld  animals 
extends  to  still  more  special  lines  of  psychological  forma- 
tion. 

Mr.  Darwin  saysf  "  All  wolves,  foxes,  jackals,  and  species 
of  the  cat  genus,  when  kept  tame,  are  most  eager  to  attack 
poultry,  sheep,  and  pigs ;  and  this  tendency  has  been  found 
incurable  in  dogs  which  have  been  brought  home  as  puppies 

*  Zoological  Journal,  p.  320.  f  Origin  of  Species,  p.  211. 


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MENTAL  EVOLUTION  IN  ANIMALS. 


from  such  countries  as  Tierra  del  Fuego  and  Australia,  where 
the  savages  do  not  keep  these  domestic  animals.*     How 
rarely,  on  the  other  hand,  do  our  civilized  dogs,  even  when 
quite  young  require  to  be  taught  not  to  attack  poultry,  sheep 
and  pigs     I7o  doubt  they  occasionally  do  make  an  attack 
and  are  then  beaten;  and,  if  not  cured,  are  destroyed:  so 
that  habit  and  some  degree  of  selection  have  probably  con- 
curred  m  civibzmg  by  inheritance  our  dogs.     On  the  other 
hand,  young  chickens  have  lost,  whoUy  by  habit,  that  fear  of 
the  dog  and  cat  which  no  doubt  was  originaUy  instinctive  in 
them ;  for  I  am  informed  by  Captain  Button  that  the  youna 
chickens  of  the  parent  stock,  ^he    Gallm  hankwa,  wheS 
reared  m  India  under  a  hen,  are  at  first  excessively  wild     So 
It  IS  with  young  pheasants  reared  in  England  under  a  hfen 
It  IS  not  that  chickens  have  lost  aU  fear,  but  fear  only  of  dogs 
and  cats;  for  if  the  hen  gives  the  danger-chuckle,  they  will 
run  (more  especiaUy  young  turkeys)  from  under  her,  and 
conceal  themselves  m  the  surrounding  thickets "    The  MS 
adds,  "Pigeons  are  not  as  constantly  kept  as  poultry,  and 
every  fancier  knows  how  difficult  it  is  to  keep  hi^  favourites 
sate  from  their  incorrigible  enemy— the  cat." 

As  additional  evidence  that  instincts  may  be  lost  or  as 
Handcock  says,  "languish"  under  domestication,  it  is  enough 
to  pointy  to  the  instinct  of  incubation  having  become  aborted 
in  the  Spanish  hen;  and  to  the  maternal  instincts  havin^r 
similarly  dwindled  in  cattle  in  certain  parts  of  Germany 
where  for  hundreds  of  generations  it  has  been  the  custom  to 
remove  the  calves  from  the  mothers  immediately  after  birth  t 
The  same  authority  says  that  sheep  will  allow  strange  lambs 
to  suck  them  m  countries  where  it  has  long  been  th?  custom 
to  change  lambs,  which  is  not  the  case  with  other  sheep. 

the  foKng^S.^  ^'^^"^  '"'^'''"'  ''''  ^^'"^^^  "  given, from  which  I  quote 

ahin  Ihth  Sir*J%TwS?f  •  ^f^^  '^"^  ^™"  Australia,  whelped  on  boaid 
■mp,  which  Sir  J.  Sebright  tned  for  a  year  to  tame,  but  which  'if  led  near 
sheep  or  poultry  became  quite  furious.'  So  again  Captain  FitzRoy  saVs  thaJ 
not  one  of  the  n,any  dogs  procured  from  the  nltiyes  of  Tiei™ X  Juego  and 
Patagonia  which  were  brought  to  England  could  easily  be  preyented  from 
indulgence  in  the  most  indiscriminate  attack  on  poultry,  younffSes  S^ 

p.  1-2.    Also  Waterton  s  Essay  on  Nat.  Hist,  p.  197,  for  extreme  wildnpso  J 

SnLt  wT  '*  "^^'  t""  't?^>  •     ^"^ tlieVss';iso conSaTe tter 5om 
Sir  James  Wilson,  giving  Mr.  Darwin  an  account  of  a  tamed  Dineo  whic^ 
obstinately  persisted  in  killing  poultry  and  ducka  wheneyer  he  got  Ee     ^ 
t  Stuorn,  Veber  Race:%,  &c.,  s.  82. 


DOMESTICATION. 


233 


-.'■-tly  according  to  Mr.  J.  Shaw,  "where  the  dog  is  valued 
solely  for  food,  as  in  the  Polynesian  Islands  and  China,  it  is 
described  as  an  extremely  stupid  animal,"*  and  White  says 
m  his  "Natural  Histoiy  of  Selborne,"t  that  these  dogs  have 
lost  some  of  what  we  must  regard  as  their  strongest  instincts, 
lor  though  they  are  so  strictly  carnivorous  animals,  from' 
having  been  for  so  many  generations  fed  on  vegetable  food 
they  have  lost  their  instinctive  taste  for  flesh." 

Thus  much,  then,  for  what  we  may  call  the  negative  in- 
fluence  of  domestication,  or  its  power  of  destroying  natural 
instincts.     We  shall  now  turn  to  the  still  more  striking  and 
suggestive  side  of  the  subject,  viz.,  the  positive  influence  of 
domestication  m  developing  new  instincts  not  natural  to  the 
species  but  artificially  produced  by  accumulative  instruction 
through  successive  generations,  combined  with  selection.  And 
here  I  shall  confine  myself  to  the  species  of  domestic  animal 
m  which  these  effects  have  been  most  conspicuous,  viz   the 
Dog.    Doubtless  the  reason  why  these  effects  are  most  con- 
spicuous in  the  case  of  this  animal  is  because  his  utility  to 
man  has  always  depended  mainly  upon  his  inteUigence,  so 
that  man  has  here  persistently  directed  the  influences  of 
domestication  towards  an  artificial  shaping  of  that  intelli- 
gence.    For  It  is  in  this  connection  of  interest  to  observe 
that  the  only  features  in  the  primitive  psychology  of  the  doer 
which  have  certainly  remained  unaffected  by  contact  with 
man,  are  those  features  which,  being  neither  useful  nor  harm- 
lul  to  man,  have  never  been  either  cultivated  or  repressed 
feuch  IS  the  case,  for  example,  with  the  instincts  of  coverin^r 
excrement,  rolling  in  filth,  turning  round  and  round  to  make 
a  bed,  hiding  food,  &c.J 

As  evidence  of  the  positive  influences  of  domestication  on 
the  psychology  of  the  dog,  I  may  first  draw  attention  to  what 
occurs  to  me  as  a  very  suggestive  case.    One  of  the  most  dis- 

■HT  *JF^^^.  sentence  occurs  as  a  quotation  in  a  letter  by  Mr.  Shaw  to 
Mr.  Darwin,  but  the  reference  is  not  supplied. 
t  Letter  57. 

*i,  hl"^  ¥'^^?®  ^"■^f  *^**  ^*  ^^  "°*  "'^ti^  <log8  are  ten  or  twelve  months  old 
that  they  begin  to  bury  superfluous  food.  This,  if  true,  would  point  to  the 
conclusion  that  the  instinct  was  one  lately  acquired  in  the  history  of  the 
wild  species,  and  therefore  presumably  is  not  so  firmly  fixed  as  the  instincts 
ot  wildness,  fierceness,  attacking  poultry,  and  so  on,  which  have  been  so 
completely  eradicated  by  human  agency. 


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234 


MENTAL  EVOLUTION  IN  ANIMALS. 


Vlll! 


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dtfillin^  wh!^^^^^^^^   "^  *^^  psychology  of  the  dog  is  the  high 
aegree  m  which  there  are  developed  the  ideas  of  ownershin 

theTwilT.t  ff^'  ^^  ""  •?•     ^°^^  carnivorous  animals  in 
caDtorT   nffl^      '"^^  ^'^  'l'^"^  P'^'P^^^y  ^«  l^elonging  to 
captors,  and  the  manner  m  which  certain  predacious  Ca?ni?ora 
take  possession  of  more  or  less  definite  areas  as  their  huntln"! 
grounds  implies  an  incipient  notion  of  the  same  thing     From 
the  germ  thus  supplied  by  nature  the  art  of  man  has%eS 
in  the  case  of  the  dog,  tiU  now  the  idea  of  defendin'Ss 
ma  ters  property  has  become  in  this  animal  truly  Istinctive 
Without  any  training,  and  even  sometimes  against  traiSn^' 
many  dogs  will  bark  and  fly  at  strangers  passfn^  thelZToi 
doors  which  bound  their  master's  premised.     Instancefw  th 
out  number  might  be  multiplied  to  show  the  care  urvtiW 
of  dogs  over  property  entrusted  to  their  charge;  but,^a    the 

fts  Vroo?  Y.bT^i:  '^'''  ""''^  ""''  ^''^  be^ccupi^d  w  ?h 
Its  proot.     I  shall,  however,  give  one  or  two  observations 

which  I  myself  made  in  this  connection  on  a  terrier  wSi 

reared  from  puppyhood,  because  I  am  perfectly  cer  a  n  that  in 

sttcZ'  .  H  '^?f  r''^"^^  P^^P^^^y  ™  innate  or  in° 
stmctive,  and  not  due  to  individual  instruction.  I  have  seen 
this  dog  escort  a  donkey  which  had  baskets  on  its  back  filled 
Tet  a  f  '•  Although  the  dog  did  not  know  that  he  was 
feni  fn7??'  ^'  ^^^°«^P^"i«d  the  donkey  all  the  way  up  a 
long  hill  for  the  express  purpose  of  guardincr  the  ancles  Fnr 
every  time  that  the  donkey  turned  back  his^ead  to  take  an 

KosT'  fndtoh"''^^  '-"r  ^P^^^"S  up  and  snapped  a" 
fi  s  nose ,  and  such  was  the  vigilance  of  the  dog  that,  althou-h 
h     companion  was  keenly  desirous  of  tastiSg  soie  of    he 

Stlf  hourTh?^^  get  a  single  apple  during  the 

halt  hour  that  they  were  left  together.  I  have  also  seen  this 
terrier  protect  ng  meat  from  oth^r  terriers,  wllh TvedTn  the 
same  house  with  him,  and  with  which  he  was  on  the  best  of 
terms.  More  curious  still,  I  have  seen  him  seize  my  wr  sf 
bands  while  they  were  being  worn  by  a  friend  to  wh7n  I  had 
temporarily  lent  them-no  doubt  recognizing  thm  S  mine 
by  his  sense  of  smell,  which  was  exceedingly  aood 

Akm  to  this  inborn  idea  of  protecting  the  property  of  his 

l^^  "t  of  fw"'"'  ''''  '^"  ^^«  of  hims^f  afcoLt  tu  ! 
ing  a  part  of  that  property— if„,  the  idea  of  ownership  as 

extended  to  himself.   That  this  idea  is  likewise  inborn  I  have 


DOMESTICATION. 


235 


observed  in  the  case  of  a  very  young  Newfoundland  puddv 
which  was  given  to  me  when  scarcely  able  to  Coddle  kft 

ctwLTelts'  '  Y.f  ^r^  '^"°"^'  ^'  throughtleibSy 

Se  from  ant  of  Z     .1  '  ^^^^^  'f °  ^""^''^^y  ^^^^  knowj 
me  irom  any  of  the  other  persons  he  met,  and  therefore  ht 

can  only  have  followed  me  from  his  instinctive  Idea  of 

ownership,  and  his  consequent  fear  of  gett  nriotf      tm! 

abstract  idea  of  ownership^  well  deveLped  iS^many  if  not 

HnTtn  fi°f  ;w  ^}'''  ^''  ^°«^^^«^>i^  i«  ^«t  -t  all  an^unusua 
thing  to  find  that  If  a  master  consigns  his  dog  to  the  care  of 
a  friend  previously  unknown  to  the  animal,  the    atter  wil 
feel  quite  safe  under  the  charge  of  one  whom  he  has  seen  to 
be  his  master's  friend.     For  the  time  being  the  allegiance  of 
the  animal  is  transferred,  and  he  feels  to  his  master?  friend 
not  as  to  a  stranger,  but  as  to  a  deputed  owneT     It  is  not  I 

sdS  JbT^^^''^''-r^''  "PP^^^«  '^  ^'  ^he  acquired  B- 
stmct  of  barking  is,  as  it  were,  an  ofFshoot  from  this  acquired 
instinct  of  property,  and  of  protecting  self  as  propeitv  bv 

or'Ses''  '''^"'""  ''  '  "^'^^^^  '^  the%proacVo?^tranVr^ 
Mr.  Darwin  has  made  a  strong  point  of  other  and  still 

more  special   "domestic  instincts "   of  the  dog    wMch  are 

fiXSoT;.'  interesting  than  those  above  mentionrd! 

trom  the  fact  of  their  having  been  intentionally  bred  into  the 

instincts  of  the  sheep-dog,  retriever,  and  pointer.  •  He  brieflv 
alludes  to  these  cases  in  the  "Origin  of  Sneciec, "  A.  9nqf 

from  which  therefore  I  shall  quote.  ' 

fprolf^r^^  ^^  -^^^  ^^''^''f^  ^'®^^«  ^f  I^ogs,  and  see  what  dif- 
ferent  tendencies  are  inherited,  many  ot^  which  caimoffmm 
being  utterly  useless  to  the  aninial,  hLe  blen  inSed  f  oS 
their  one  or  several  wild  prototypes.      I  have  talked  wS 

m  saying  that  occasionally  a  young  sheep  dog  without  anv 

S  aiurorr'^h^  '''''  '"^  ^"^  ^°^"d^^he  flock,  an  J 

that  all  thorough-brea  dogs  can  be  easily  taught  to  do  this- 

pugnacity  yet  they  do  not  worry  the  sheep,  as  auv  wild 
canine  animal  of  the  same  size  wmdd  do.  Look  aoaTnVthe 
Eetriever  which  so  naturally  takes  to  brin.nn<7back\nv 
object  to  his  master.    The  pj.  W.  D.  Fox  iSms  me  tS 


■U 


)  1    ,1  j:  . 


!l 


1  ■■ ' 


I  i  •  #1 


236 


i 


■iJj! 


:  f 


MENTAL  EVOLUTION  IN  ANIMALS. 


he  taught  in  a  single  morning  a  Eetriever  six  months  old  to 
fetch  and  carry  well,  and  in  a  second  morning  to  return  on 
the  path  to  search  for  an  object  left  purposely  behind  and  not 
seen  by  the  dog.  Yet  I  know  from  experience  how  difficult 
it  is  to  teach  the  habit  at  least  to  terriers. 

"  Let  us  consider  one  other  case,  though  so  often  quoted, 
that  of  the  Pointer.  I  have  myself  gone  out  with  a  young 
dog  for  the  first  time,  and  his  innate  tendency  was  shown  in 
a  ludicrous  manner,  for  he  pointed  fixedly  not  only  at  the 
scent  of  game,  but  at  sheep  and  large  white  stones ;  and 
when  he  found  a  lark's  nest,  we  were  actually  compelled  to 
carry  him  along;  he  backed  the  other  dogs.  .  .  .  The 
silence  of  Pointers,  also,  is  the  more  remarkable,  as  all  who 
have  studied  these  dogs  agree  in  classing  them  as  a  sub-breed 
of  Hound,  which  gives  tongue  so  freely.  But  the  tendency 
in  the  young  Pointer  to  back  other  dogs,  or  to  point  without 
perceiving  any  scent  of  game  when  they  ee  other  dogs 
point,  is  perhaps  the  most  singular  part  of  ias  inborn  pro- 
pensities.* 

"  Now  if  we  were  to  see  one  kind  of  wolf,  in  a  state  of 
nature,  running  round  a  herd  of  deer,  and  skilfully  driving 
them  whither  he  liked,  and  another  species  of  wolf,  instead 
of  chasing  its  prey,  standing  silent  and  motionless  on  the 
scent  for  more  than  half  an  hour  with  the  other  wolves  of  the 
pack  all  assuming  the  same  statue-like  attitude  and  cautiously 
approaching,  we  should  surely  call  these  actions  instinctive. 
The  chief  characteristics  of  instinct  seem  to  be  fulfilled  in  the 
pointer.  A  young  dog  cannot  be  supposed  to  know  why  he 
points,  any  more  than  a  butterfly  why  it  lays  its  eggs  on  a 

cabbage It  seems  to  me  to  make  no  essential 

difference  that  pointing  is  of  no  use  to  the  dog,  only  to  man ; 
for  the  habit  has  been  acquired  through  artificial  selection 
and  training  for  the  good  of  man,  whereas  ordinary  instincts 
are  acquired  through  natural  selection  and  training  exclu- 
sively for  the  animal's  own  good.  The  young  pointer  often 
points  without  any  instruction,  imitation,  or  experience; 
though,  no  doubt,  as  we  have  also  seen  sometimes  to  be  the 

•  "With  respect  to  the  inherited  tendency  to  back,  see  St.  John't 
Wild  Sport  of  the  Highlands,  1846,  p.  116 ;  Colonel  Hutcliinson  on  Bog 
Breaking,  1850,  p.  144;  and  Blaine,  Ency.  of  Rural  Sports,  p.  791.— Besides 
the  tendency  to  point,  pointers  inherit  a  peculiar  mann»r  of  quartering  their 
ground." 


,  in; 

"III' 


DOMESTICATION. 


237 


case  with  trae  instincts,  he  often  profits  by  these  aids   More- 

?ro'pensitt  ''  ''''^"'''  "  '°^'°"'^«"  '^^  ^^^"'^ 

"  The  most  important  distinction  between  pointincr  &c 
and  a  true  instmct,  is  that  the  former  is  less  strictly  inhe'rited* 
and  vanes  greatly  in  the  degree  of  its  inborn  peSon  •• 
this    however,  is  just  what  one  might  have  expected    fo; 
both  mental  and  corporeal  characters  are  less  true  in  domestic 

c^'Sions  oVlV^°"/'  -  «tate  of  nature,  inasmuch  as  the  r 
conditions  of  life  are  less  constant  and  man's  selection  and 
training  far  less  uniform,  and  have  been  continued  fVan 
ducS?^  ^  shorter  period,  than  is  the  case  in  nature'^pro- 

^      Although  the  familiar  fact  of  young  pointers  pointin^^' 
instinctively  does  not  need  further  corroboraLn Jshall quotf 
a  brief  passage  from  the  paper  of  Mr.  Andrew  Kntht  on 

bacJiing,    to  what  extreme  mcety  of  detail  the  hereditary 
knowledge  may  m  some  cases  extend.  ^«ieuitary 

inrlllVLri^  ^''T''  *^^^  "^''^  3^°""S  P^i^ters,  of  slow  and 
indolent  breeds,  wil  point  partridges  without  any  previous 
instruction  or  practice.  I  took  one  of  them  to  a  spoUvTere 
I  had  just  seen  a  covey  of  small  partridges  alight  in  August 
and  amongst  them  I  threw  a  piece  of  brSad  to  Induce  ^0'' 
to  move  from  my  heels,  which  it  had  very  little  dispos'tioS 
to  do  at  any  time  except  in  search  of  something  to  e^t.  On 
getting  among  the  partridges,  and  perceiving  the  scent  of 

^i^Uf'STf^'fr  ^"ddenly  fixed,  and  its^muscles  rigid 
and  It  stood  trembling  with  anxiety  for  several  minutes  I 
then  caused  the  birds  to  take  wing,  at  sight  of  which  it 
exhibited  strong  symptoms  of  fear  an^d  noneV  pleasure  1 
young  Springing  Spaniel,   under  the    same  circumstances" 

ruUbrtb'off^''""'^^-'^^^^  exultation,  and  I  do  not 
nonP  nf  f  the  young  pointer  would  have  done  so  too,  if 
none  ot  its  ancestry  had  ever  been  beaten  for  sprino/nc 
partridges  improperly."  f^"'©"'© 

From  this  same  paper  I  must  quote  the  following  and 
more  or  less  analogous  cases  :—  "^ 

in  LI  >'°""S  Terrier  whose  parents  had  been  much  employed 
m  destroying  Polecats,  and  a  young  Springing  Spaniel  wh^ose 


\l'\ 


•    n 


I     'M 


1      :i 


-i\    \':i 


I  i 


16 


Phil.  Tram.,  1837,  p.  367. 


! 

I 

.i 

', , 

4 

';, , 

1, 


\i\ 


:i' 


ifiiii' 


238 


MENTAL  EVOLUTION  IN  ANIMALS. 


n     f  1 


ancestry  through  many  generations  had  been  employed  in 
finding  Woodcocks  were  reared  together  as  companions,  the 
Terrier  not  having  been  permitted  to  see  a  Polecat  or  any 
other  animal  of  similar  character,  and  the  Spaniel  having 
been  prevented  seeing  a  Woodcock  or  other  kind  of  game. 
The  Terrier  evinced,  as  soon  as  it  perceived  the  scent  of 
the  Polecat,  very  violent  anger ;  and  as  soon  as  it  saw  the 
Polecat  attacked  it  with  the  same  degree  of  fury  as  its 
parents  would  have  done.  The  young  Spaniel,  on  the  con- 
trary, looked  on  with  indifference,  but  it  pursued  the  first 
Woodcock  it  ever  saw  with  joy  and  exultation,  of  which  its 
companion,  the  Temer,  did  not  in  any  degree  partake.  .  . 
In  several  instances  young  and  wholly  inexperienced  dogs 
appeared  very  nearly  as  expert  in  finding  Woodcocks  as  their 
experienced  parents. 

"Woodcocks  are  driven  in  frosty  weather,  as  is  well 
known,  to  seek  their  food  in  springs  and  rills  of  un'Vozen 
water,  and  I  found  that  my  old  dogs  knew  about  as  well  as  I 
did  the  degree  of  frost  which  would  drive  the  woodcocks  to 
such  places ;  and  this  knowledge  proved  very  troublesome  to 
me,  for  I  could  not  sufficiently  restrain  them.  I  therefore  left 
the  old  experienced  dogs  at  home,  and  took  only  the  wholly 
inexperienced  young  dogs  ;  but  to  my  astonishment  some  of 
them,  in  several  instances,  confined  themselves  as  closely  to 
the  unfrozen  grounds  as  their  parents  would  have  done. 
When  I  first  observed  this  I  suspected  that  woodcocks  might 
have  been  upon  the  unfrozen  ground  during  the  preceding 
night,  but  I  could  not  discover  (as  I  think  I  should  have 
done  had  this  been  the  case)  any  traces  of  their  having  been 
there ;  and  as  I  could  not  do  so,  I  was  led  to  conclude  that 
the  young  dogs  were  guided  by  feelings  and  propensities 
similar  to  those  of  their  parents." 

Elsewhere  in  his  essay  this  author  remarks,  "  It  m.ay,  I 
think,  be  reasonably  doubted  whether  any  dog  having  the 
habits  and  propensities  of  the  Springing  Spaniel  would  ever 
have  been  known,  if  the  art  of  shooting  birds  on  the  wing 
had  not  been  acquired." 

Lastly,  with  reference  to  those  artificial  instincts  of  the 
dog,  which  are  of  this  highly  specialized  nature — amounting, 
in  fact,  to  hereditary  memory  of  a  most  minute  kind — I 
may  allude  to  a  remark  made  by  Professor  Hermann,  that 
sporting  dogs  appear,  when  first  taken  out  to  hunt,  and  there- 


DOMESTICATION, 


239 


fore  previous  to  any  individual  experience,  to  anticipate  the 
ettects  ot  a  gun  m  bringing  down  a  bird .♦ 

Suggestive,  however,  as  is  the  formation  by  man  of  such 
special  canine  instincts  as  we  have  now  considered  we  have 
m  them  only,  as  it  were,  smaU  details  of  the  modification 
which  human  agency  has  produced  in  the  psychology  of  the 

^^\  }  I^'  "^^^^^  "^^^  ^°^^  ^^"^^  ^^^^  inan  has  in  a  sense 
created  the  remarkable  structure  of  the  greyhound  or  the 
bulldog,  than  that  he  has  implanted  the  no  less  remarkable 
instincts  of  the  pointer  or  the  retriever ;  but  we  should  gain 
a  very  inadequate  conception  of  the  profound  influence  which 
he  has  exercised  in  moulding  the  mind  of  this  animal  were 
we  to  confane  our  attention  to  such  special  cases  as  these 

vw7f  contrast  the  psychology  of  "the  friend  of  man" 
with  that  of  any  of  the  wild  breeds,  we  see  at  once,  not  only 
that  the  animal  has  had  many  of  its  natural  instincts  sup- 
pressed and  many  artificial  instincts  imposed,  but  also  that  it 
has  acquired  as  Sir  J.  Sebright  has  observed,  "an  instinctive 
love  of  man       But  the  general  affection,  faithfulness,  and 
docility  of  the  dog,  are  too  proverbial  to  need  special  exposi- 
tion  We  have  merely  to  observe  that  these  qualities,  so  unlike 
anythmg  with  which  we  meet  in  wolves,  foxes,  jackals,  and 
wild  dogs  generally,  can  only  be  attributed  to  prolon^red 
contact  with,  and  selection  by,  his  human  masters ;  so  that 
as  the  domestic  dog  is  at  present  constituted  these  artificiaUv 
imposed  qualities  usually  lead  the  animal  to  entertain  higher 
attection  and  faithfulness  towards  man  than  towards  its  own 
kind     It  may  not  be  superfluous  in  this  connection  again  to 
point  out  that  among  wild  animals  we  do  not  unfrequently 
hnd  a  disposition  to  associate  with  members  of  other  species 
even  when  no  actual  benefit  arises  from  the  association  ;  and 
m  this  accidental  or  useless  proclivity  we  may  distinguish 
the  germ  which  m  the  case  of  the  dog  has  been  cultured  into 
what  we  see— amply  justifying  the  remark  of  the  old  writer 
quoted  by  Darwin,  "A  dog  is  the  only  thing  on  this  earth 
that  luvs  you  more  than  he  luvs  himself." 

Not  only  affection,  faithfulness,  and  docility,  but  Hkewise 
all  other  emotional  qualities  of  the  dog  which  are  useful  to 
man  have  been  developed  by  man  to  the  extraordinary 
degree  which  we  observe.    It  would  be  superfluous  to  cite, 

•  Eandbuvh  der  Fhysiologie,  Bd.  II,  Theil  II,  pp.  282-8. 


s.   ! 


B 


hi: 


tj'^ii: 


"  "I, 


tin  '; 


h'l 


240 


MENTAL  EVOLUTION  IN  ANIMALS. 


or  even  to  give  references  to  cases  illustrating  the  exalted 
level  to  which  sympathy  has  attained.  This,  together  with 
the  intelligent  affection  from  which  it  springs,  gives  rise  to  a 
love  of  approbation  and  dread  of  blame,  which  as  far  as  they 
go  are  in  no  way  distinguishable  from  the  same  feelings  as 
they  occur  in  man  himself.  To  this  subject  I  shall  have  to 
return  when  in  my  next  work  we  come  to  treat  of  the  genesis 
of  Conscience. 

Again,  as  Mr.  Grant  Allen  has  pointed  out,  the  sense  of 
dependence  which  a  dog  shows  is  very  instructive.  "The 
original  dog,  who  was  a  wolf  or  something  very  like  it,  could 
not  have  had  any  such  artificial  feeling.  He  was  an  inde- 
pendent, self-reliant  animal.  .  .  .  But  at  least  as  early 
as  the  days  of  the  Danish  shell-mounds,  perhaps  thousands 
of  years  earlier,  man  had  learned  to  tame  the  dog."  There- 
fore, as  a  result  of  continuous  education,  selection,  and  breed- 
ing, althoug-i  "  among  a  few  dogs,  like  those  of  Constanti- 
nople, the  instinct  may  have  died  out  by  disuse 

when  a  dog  is  brought  up  from  puppyhood  under  a  master, 
the  instinct  is  fully  and  freely  developed,  and  the  masterless 
condition  is  thenceforth  for  him  a  thwarting  and  disappoint- 
ing of  all  his  natural  feelings  and  affections."* 

Indeed,  so  strong  are  the  combined  effects  of  long-con- 
tinued breeding  and  individual  education,  that  they  may 
overcome  the  strongest  of  natural  instincts  and  desires — 
witness  a  dog  which  will  starve  rather  than  steal,  and  also 
the  recorded  cases  in  which  even  the  maternal  instinct  has 
been  overborne  by  the  desire  of  serving  a  master.  To  give 
only  one  example  of  this  surprising  fact,  I  shall  quote  from 
the  "  Shepherd's  Calendar  "  of  the  poet  Hogg  : — 

A  collie  belonged  to  a  man  named  Steele,  who  was  in 
the  habit  of  consigning  sheep  to  her  charge  without  super- 
vision. On  one  occasion,  says  Hogg,  "whether  Steele 
reriiained  behind  or  took  another  road,  I  know  not,  but,  on 
arriv  .ng  home  late  in  the  evening,  he  was  astonished  to  hear 
that  his  faithful  animal  had  never  made  her  appearance  with 
the  drove.  He  and  his  son,  or  servant,  instantly  prepared  to 
set  out  by  different  paths  in  search  of  her,  but  on  their  going 
out  into  the  streets,  there  was  she  coming  with  the  drove,  not 
one  missing,  and,  marvellous  to  relate,  she  was  carrying  a 
young  pup  in  her  mouth.     She  had  been  taken  in  travail  on 

•  Evolutionist  Ahmad,  p.  182,  et  sej. 


tr: 


DOMESTICATION. 


241 


the  hills,  and  how  the  poor  beast  had-  contrived  to  manacre 
her  drove  in  her  state  of  suffering  is  beyond  human  calcula- 
tion, tor  her  road  lay  through  sheep  the  whole  way.  Her 
master's  heart  smote  him  when  he  saw  what  she  had  suffered 
and  effected;  but  she  was  nothing  daunted,  and,  havinc/ 
deposited  her  young  one  in  a  place  of  safety,  she  again  set' 
out  full  speed  to  the  hills  and  brought  another  and  another 
till  she  brought  her  whole  litter,  one  by  one ;  but  the  last  one 
was  dead, 

_  There  is  still  one  respect— and  this  a  most  suggestive  one 
—m  which  artificial  instincts  resemble  natural  instincts,  over 
and  above  that  of  obliteration  by  disuse  or  acquirement  by 
training  and  selection.  In  order  to  show  this  it  will  be  suffi- 
cient to  quote  the  following  passage  from  Mr.  Darwin's  MSS 
part  of  which  has  already  been  published  in  the  "  Variation 
of  Animals  and  Plants  under  Domestication "  (vol.  i 
p.  43) : —  ' 

"  It  is  well  known  that  when  two  distinct  species  are 
crossed,  the  instincts  are  curiously  blended,  and  vary  in  the 
successive  generations,  just  like  corporeal  structures      To 
give  an  example:  a  dog  kept  by  Jenner  (Hunter's  "Animal 
Econoniy,' p.  325),  which  was  grandchild,  or  had  a  quarter- 
blood  of  the  jackal  m  it,  was  easily  startled,  was  inattentive 
to  the  whistle,  and  would  steal  into  fields  and  catch  mice  in 
a  peculiar  manner.     Now  I  could  give  numerous  examples  of 
crosses  between  breeds  of  dogs,  both  having  artificial  instincts, 
m  which  these  instincts  have  been  most  curiously  blended 
as  between  the  Scotch  and  English  sheep-dog,  pointer  and 
setter :  the  effect,  moreover,  of  such  crosses  can  sometimes  be 
traced  for  very  many  generations,  as  in  the  courage  acquired 
by  Lord  Orford's  famous  greyhounds  from  a  single  cross  with 
the  bull-dog  ("  Youatt  on  the  Dog,"  p.  31).     On  the  other 
hand,  a  dash  of  the  greyhound  will  give  a  family  of  sheep- 
dogs a  tendency  to  hunt  hares,  as  I  was  assured  by  an  intel- 
ligent shepherd." 

Our  a  posteriori  proof  of  Proposition  VII  is  now  concluded, 
and  with  its  proof  our  considerations  on  the  origin  and' 
development  of  instinct  are  drawing  to  a  close.  For  we  have 
now  seen  that  instincts  may  arise  under  the  influence  of 
natural  selection  alone,  under  that  of  lapsing  intelligence 
alone,  or  under  both  these  influences  combined.    And  in 


m 


II: 


'i  i 


242 


MENTAL  EVOLUTION  IN  ANIMALS. 


proving  that  habits  intelligently  acquired  may,  like  habits 
acquired  without  intelligence,  bo  inherited,   we  have  also 
proved,  as  in  the  analogous  case  of  primary  instincts,  that 
tnese  habits  m  the  course  of  generations  may  vary,  that  their 
variations  maybe  inherited,  and  that  the  favourable  variations 
may  be  fixed  and  further  intensified  by  natural  or  artificial 
selection.     For  it  is  only  by  granting  all  tliese  statements 
that  we  can  possibly  explain  many  of  the  foregoing  facts 
Uearly  man  could  never  have  produced  the  artificial  instincts 
ot  the  dog,  unless  he  had  practically  recognized  the  facts  of 
variability  and  inheritance- a  recognition  which  is  forcibly 
expressed  in   the  immense  difference  between  the  market 
value  of  a  pointer  or  setter  of  important  pedigree    and  a 
pointer  or  setter  whose  parentage  is  unknown.     As  Thompson 
well  says:— ;' It  would  be  necessary  to  recommence  the  busi- 
ness ot  training  with  each  successive  generation,  if  the  bodily 
and  mental  changes  which  the  animals  have  undergone  in  the 
continued  process  of  domestication  had  not  become  so  en- 
gratted  as  to  be  propagated   with    them.  -These  acquired 
characteristics  have  gathered  fresh  strength  in  each  succeed- 
ing generation,  till  at  length  they  have  assumed  a  perrnanent 
stamp.      And  if  artificial  selection  is  of  such  high  importance 
m  the  formation   of  domestic  instincts,   much  more  must 
natural  selection  be  of  importance  in  the  formation  of  natural 
instincts. 


LOCAL  AND  SPECIFIC  VARIETIES  OP  INSTINCT.  243 


CHAPTER  XVL 

Instinct  (continued). 

Local  and  Specifio  Varieties  of  Instinct. 

I  have  now  shown  that  instincts  may  arise  through  the 
mtluence  of  natural  selection,  or  of  lapsing  inteUigenc?.  or  of 
both  these  principles  combined;  and  that  even  fuUy  formed 
instincts  are  liable  to  change  when  changing  circumstances 
require     The  most  striking  evidence  on  this  head,  or  that  of 
the  mutability  of  fully  formed    instincts,  is  perhaps   the 
evidence  given  m  the  last  chapter,  showing  the  influence  of 
domestication  both  m  obliterating  the  strongest  of  natural 
and  m  creating  the  most  fantastic  of  artificial  instincts     But 
inasmuch  as  we  have  previously  seen  that  any  considerable 
change  in  the  circumstances  to  which  an  instinct  is  appro- 
priate is  apt  to  throw  the  machinery  of  that  instinct  out  of 
gear,  the  evidence  of  the  mutability  of  instinct  drawn  from 
the  effects  of  domestication  may  be  open  to  the  criticism  that 
the  changes  produced  are  of  an  unnatural  character,  or  due  to 
an  impairment  of  the  normal  apparatus  of  instinct.     I  do  not 
myself  think  that  if  this  criticism  were  raised  it  would  be 
one  of  any  force,  seeing  that  domestication  not  only  has  the 
negative  effect  of  impairing  or  destroying  natural  instincts 
but  also,  as  I  have  said,  the  positive  effect  of  creating  artifi- 
cial instincts     Still  it  is  desirable  to  supplement  the  evidence 
drawn  from  the  facts  of  domestication  with  further  evidence 
drawn  from  the  field  of  nature;  for  here,  at  least,  no  criticism 
of  the  kind  which  I  have  suggested  can  be  advanced.     T  pro- 
pose, therefore,  in  this  chapter  to  consider  all  the  facts  which 
1  have  been  able  to  collect,  tending  to  show  that  amon^ 
animals  m  a  state  of  nature  instincts  undergo  tram  formations 
which  are  precisely  analogous  to  those  that  they  undergo 


■^•■ti^ 


-n 


m^ 


If 


i 


if. 


244 


MENTAL  EVOLUTION  IN  ANIMALS. 


■fi   ,! 


\y. 


1    :!111 


among  animals  in  a  state  of  domostioation.     Tlio  kind  of 
evidence  on  which  I  rely  to  show  this  is  two-fold-lst  tl^ 

and  2ud  the  similar  occurrence  of  specific  varieties. 

Zom/  Varieties  of  Instinct. 

thnf^fHf""  ^^^^^.^tof  these  two  divisions  I  shall  seek  to  show 
that  the  mutahdity  of  instinct  finds  a  most  marked  and  su- 
gestive  expression  m  certain  cases  where  wild  animals  of  the 
same  species  living  m  diiferent  parts  of  the  world  (and  there- 
fore exposed  to  different  environments),  present  differencesTn 
their  instinctive  endowments  of  a  marked  and  cons  an?  k  nd 
One  class  of  such  cases  has  already  been  given  with  reference 
to  the  acquisition  of  an  instinctive  fea?  of  man  Ty  those 
animals  in  a  state  of  nature  which  inhabit  localities  frequented 
by  man :  bu  as  the  subject  appears  to  me  an  important  one 
seeing  that  a  definite  local  variety  is  on  its  way  to  becom! 
mg  a  new  instinct-I  shall  now  give  all  the  best  instances 
which  I  have  been  able  to  collect  icscances 

Beginniiig  with  insects,  Kirby  and  Spence  state  on  the 
authority  of  Sturm  that  the  dung-beetle,  which  rolls   ud 
pellets  or  little  baUs  of  dung,  sav°es  itseif  the  tmuble  of 
making  the  pellets   when  it  happens   to   live    on    sleep 
pasures;  for  it  then  "avails  itself  of  the  pellet-shaped  baffs 

suppl  es.      Here  we  have  intelligent  adaptation  to  peculiar 

thelT'.-r^' •  '^.'  'f^^^^'  l^^ve  beeS  quoted  as  one  o 
the  plasticity  of  instinct;  but  as  sheep-pastures  are  definite 

instinct.  All  cases  of  such  local  variation  must  have  some 
determining  cause,  and  doubtless  most  frequently  this  cau  e 
IS  intehgent  adaptation  to  peculiar  local  conditions.  There! 
fore  I  have  chosen  this  case  to  lead  off  with  iust  because  it 

7^lr^^  ^"^  ^"  ^"'''^  ^°  '^'  ''  ^"  the  previous 
Again  it  is  stated  by  Lor.fciere,  in  his  history  of  Siam 
that  in  one  part  of  that  kingdom.,  which  lies  open  to  4at' 
munda  ions,  all  the  ants  made  their  settlements  upon  treet- 
no  ants  nests  are  to  be  seen  anywhere  else."  And  Forel 
states  a  closely  similar  fact  with  reference  to  a  species  o 
European  ant,  lasms  accrhorum,  which  on  the  plains  is  never 


LOCAL  AND   SPECIFIC  VARIETIES  OP  INSTINCT.  245 

fouiid  to  build  under  stones,  while  in  the  Alps  it  frequently 
builds  under  the  same  stones  as  the  Myrmica  '=*i"«"''^y 

ana  Laiitoima  the  hive-bees  when  introduced  "  retain  their 
ndustrious  habits  only  for  the  first  two  or  three  years.  After 
that  time  they  gradually  cease  to  collect  honey  till  thev 
become  wholly  idle."*  Again.  Mr.  Packard,  jun..  recoils 
some  observationsf  which  were  made  by  the  Kev  L  Thonm- 
son  whom  he  designates  "a  careful  observer."  of  bees  (Apia 
mellzfica)  eatw^^  motlis   which  were   entrapped   in   certain 

wrnr;T,«?iJ  !f/^f  ^'"'^  communicated  to  Mr.  Darwin,  he 
wrote,  that  he  "had  never  heard  of  bees  being  in  any  way 
carnivorous,  and  the  fact  is  to  me  incredible.  Is  it  possible 
that  the  bees  opened  the  bodies  of  the  Flusia  to  suck  the 
nectar  contained  in  their  bodies  ?  Such  a  degree  of  reason 
would  require  confirmation,  and  would  be  very  wonderful'' 
But  whatever  the  object  of  the  bees  may  have  been  their 
actions,  which   are  described  as  "suddenly  dartin-''   and 

lurious.   certainly  display  some  marked  variation  of  Instinct 
under  the  guidance  of  intelligence.     Moreover,  the  explana- 
tion entertained  by  Messrs.  Thompson  and   Packard-viz 
that  the  bees    were  partly  carnivorous,  is  perhaps  not  so 

incredible    as  it  appeared  to  Mr.  Darwiu.  if  we  remember 
tastesT'^'  ^'^  unquestionably  apt  to  develop  carnivoroua 

Turning  now  to  local  variations  of  instinct  in  Birds   I 
may  first  allude  to  the  foUowing  instances  in  the  Append^ 
which  although  not  adduced  in  this    connection  by  Mr' 
Darwin,  are  no  less  apposite  to  it.  ^ 

A-w"^^i^  "°^o"ous  that  the  same  species  of  bird  has  sliohtly 
different  vocal  powers  in  diflerent  districts;  and  an  excellent 
observer  remarks,  'an  Irish  covey  of  partridges  sprincrs  with- 
out uttering  a  cal .  whilst  on  the  opposite  Soasttlie"  Scotch 

8a>s  that  Irom  many  years'  experience  he  is  certain  that  in 

•KivhA'!!^^  ^"^'"''ff'ff'  P-  188,  where  see  for  references  to  Dr.  E.  Darwin 
Kirby  and  Spenco,  and  later  writers  on  this  matter.  -L'arwin. 

T  American  Naturalist,  Jan.  1880 

Tations'of  ?h;Srh'  «°^-  n^'^P.f^l'  *^*'  ^^^'  *"^  663,  detaihng  obser- 
Bod!and  wl'a.Sith^.^"  ^'  ^^^^^'burn.  Messrs.  Newall,  F.eI,  Lewi. 

§  W.  Thompson,  in  Wat.  Hist.  Ireland,  vol,  ii,  p  65  savs  he  hn.R  nH««. ..  i 
this,  and  that  it  is  weU  known  to  sportsmen.  ^      '  ^  oh^ovy^d 


■M-l* 


(  .. 


\'' 


246 


MENTAL  EVOLUTION  IN  ANIMALS. 


f  f 


1 . 


Vnl 


nl'hfof  t^tlf//'"'^'"'^  -^"/^"^  ^^  *^«  middle  of  the 

hented!^'*  ^^  ''''''  ""  ^^^"'  ^°^  ^«  ^^^^tly  in- 

Professor  Newton  informs  me  that  the  Eing-plover  on 

^sVafsT;:rot'"""  ''/-'''''''  ^^^  Suffolk'hTbltually 
aisplays  a  yeiy  curious  and  instructive  case.     These  birdi 

naturally  Md  on  the  sea-shore,  depositing  their  ea.s  in  a 
hollow  which  they  scoop  out  in  the  shinSe     The°sea  has 

wS  W  f ''''""  *'^  'f'^''^'  sand^unes  in  qrstion 
which  have   become  covered  with  grass.     Apparentlv  the 
Emg-plovers  have  gone  on  breeding  for  numberiess 'enera! 
tK)ns  on  the  site  which  was  at  one  time  the  sea  cr^^t  thl 
distance  between  them  and  the  sea  having  therefore  ^^^^^^^^^^ 
increased  more  and  more.f    Hence  the  birds  are  n^rS 
on  wide  grassy  surfaces  instead  of  on  shingle   but  the^? 
mstmct  of  laymg  their  eggs  on  stones  remains  fso  that  after 
having  scooped  out  a  hollow  in  the  ground,  they  collect  small 
stones  from  all  quarters  and  deposit'them  in  the^hoUow    This 
has  the  effect  of  rendering  their  nests  very  conspSs  and 
tiie  fact  shows  m  a  striking  way  how  a  fixed  ancestoUnstinct 
may,  while  m  the  main  persisting  under  changed  condit  ons 
oLaS-  ^"^^^?^^le««  ?o  vary  in  reference  to  these  changed 
conditions  as  to  constitute  the  beginning  of  a  new  instinct 

r,.,f  H  -S'^^'V"'^^"'.''  °^^°^^1  ^^ri^tion  in  the  instincts  of 
nest-bui  ding,  I  may  in  this  connection  again  refer  to  the 

tS  'TT'^'t  '''^'  P^^^^^^^ly  ^^^tioned  i^  illus! 
tration  of  the  plasticity  of  instinct  under  the  mou  din. 
influence  of  intelligence.J  I  allude  to  the  fact  thaTon  hf 
American  Continent  various  species  of  birds-notably  a  kind 
of  Owl,  a  Blue-bird,  the   Pewit  Flycatcher,  several  specTes 

fri  Yfl  ^""^  ""^^'^y  ^^1  *^«  species  of  Swallow-have 
adapted  the  structure  of  their  nests  to  the  artificiallstina! 
places  provided  by  man,  in  just  the  same  way  (though  more 
gradually  and  on  a  much  larger  scale)  as  did  he  cSlonTof 
Palm-swifts  m  Jamaica.     But  with  still  more  speciaSr- 

fere:t^"iSLT24''''  "^  ^"^  ^^^'^"^  ^^^^  ^^  singing  in  dif. 
X^leX^^"""'  ^'  ^'^'     ^'"^P'^^   '^''  °^'"y  «^  *^«  '"^^e^  given  i::  ... 


LOCAL  AND  SPECIFIC  VARIETIES  OP  INSTINCT.  247 

ence  to  the  local  variation  of  instinct,  I  may  here  quote  a 
further  statement  from  Captain  Coues'  work  previously 
cited;  for  it  shows  that  even  on  different  parts  of  the 
American  Continent  the  same  species  of  birds  exhibit  these 
differences  m  their  mode  of  nest-building.  He  says:—"  There 
is  no  question  of  the  fact  that  some  of  the  Swallows  which  in 
the  East  now  invariably  avail  themselves  of  the  accommo 
dation  man  furnishes,  in  the  West  live  still  in  holes  in 
trees,  rocks,  or  the  ground ;"  and  he  proceeds  to  give  several 
special  mstances.*  Lastly,  the  fact  has  already  been  noted 
that  House-sparrows  exhibit  a  similar  local  variation  of 
instinct  wherever  they  come  into  contact  with  the  dwellinos 
of  man.t  ° 

_    Passing  on  now  to  other  animals,  we  find  several  instruc- 
tive cases  of  the  local  variation  of  instinct  among  the  Mam- 
malia.    Thus  the  curious  habit  Las  been  observed  amon^ 
cattle  inhabiting  certain  districts  of  sucking  bones.      Arch° 
bishop  Whately  made  this  the  subject  of  a  communication 
to  the   Dublin  Natural  History  Society  many  years  aero 
Eecently  it  has  been  observed  by  Mr.  Donovan  of  cattlein 
mtal,t  and  by  Mr.  Le  Conte,  of  cattle  in  the  United  States.5 
Probably  this  habit  is  induced  by  the  absence  of  some  con- 
stituent of  food  in  the  grass  which  is  supplied  by  the  bones 
and  therefore  if  the  habit  happened  to  prove  beneficial  to  the 
cattle  (instead  of  deleterious  as  Whately  asserts),  it  is  easy 
to  see  that  cattle  in  a  state  of  nature  might  become  trans- 
muted from  herbivorous  to  omnivorous,  or  even  purely  car- 
nivorous.     Probably  the  ancestors  of  the  Pig  have  ppssed 
ttirough  the  former  of  these  stages.     On  the  other  hand,  the 
Bear  seems  to  be  in  process  of  becoming  omnivorous  from 
the  contrary  direction— being  carnivorous  in  its  affinities  but 
not  infrequently  adopting  the  habit  of  eating  grass  and  herbs. 
And  in  this  connection  I  may  refer  to  an  interesting  case 
of  transition  from  herbivorous  to  carnivorous  habits  which 
was  published  at  the  Academy  of  Natural  Science  of  Phila- 

TiT  *£i^'  "'i''  ?;.^^,*'  ^^'^  ^^*'  ^  *^'"'''  *®"^^  '«  confirm  the  statement  of 
Mr.  Edward  {Zool  p.  6842)  that  on  the  coast  of  Banffshire  the  house- 
flwallow  presents  a  local  instinct  of  building  in  caves  and  on  proiecting  rocks 

t  When  house-sparrows  build  in  trees— wliich  they  occasionally  do  and 
which  must  be  regarded  as  reversion  to  primitive  instinct-"  the  stmcture  i« 
Tery  large  more  than  a  yard  in  circumfeience,  and  covered  with  a  dome." 
(larrel's  Brituh  Birds,  4tli  Ed.,  Pt.  X,  p.  90.) 

X  Nature,  vol,  xx,  p.  457.  §  Ibid. 


■t       A 


I  if  hM 

III    'I       I     •* 


1.  H 


248 


MENTAL  EVOLUTION  IN  ANIMALS. 


(<) 


» ' 


delphia  on  February  18th,  1873,  by  Mr.  W.  K.  G.  Gentry.  A 
rodent  popularly  known  as  the  Chickaree  (Scinus  hwlsmius), 

IdZL  ^  T^  ^^  •'l'.^^?  ''  °°^°^^"y  herbivorous,  has 
adopted  m  the  neighbourhood  of  Mount  Airy  a  habit 
common  among  the  Mustelidw,  of  climbing  trees  for  the  pur- 
pose of  catching  birds  and  sucking  their  blood.  Mr.  Gentry 
suggests  that  this  transition  from  herbivorous  to  carnivorous 
Habits  may  have  arisen  from  the  propensity  shown  by  some 

Et'/.'"f  ^"^  '^'  ^P.^f  birds-the  passage  from  this 
habit  to  that  of  suckmg  the  blood  of  birds  bein|  but  small, 
i^astly  m  this  connection  I  may  adduce  a  precisely  analogous 
case  of  a  marked  local  variation  of  instinct  taking  place  in  a 
species  of  bird.  °  ^ 

Mr  I.  H.  Potts,  writing  from  Ohinitahi  to  "  Nature"  (Feb- 

!!!M7  f '  .?'  'T,  *^^^  *^^  mountain  parrot  (Nestor 
notahhs)  was  then  exhibiting  a  "progressive  development  of 
change  m  habits  from  the  simple  tastes  of  a  honey-eater  to 
the  savageness  of  a  tearer  of  flesh."  For  « the  birds  come  in 
flocks,  single  out  a  sheep  at  random,  and  each  ahghting  on 

ilL^^f^/fi,*'''''^  *'f'  °^*  *^^  ^°°1'  ^"^  makes  the  sheep 
bleed  till  the  animal  runs  away  from  the  rest  of  the  sheep. 
Ihe  birds  then  pursue  it,  and  force  it  to  run  about  tOl  it 
becomes  stupid  and  exhausted.  If  in  that  state  it  throws 
Itself  down,  and  lies  as  much  as  possible  on  its  back  to  keep 
the  birds  from  picking  the  part  attacked,  they  then  pick  a 
tresh  hole  in  its  side,  and  the  sheep,  when  so  set  upon,  in  some 
instances  dies  .  .  Here  we  have  an  indigenous  species 
making  use  of  a  recently  imported  aid  for  subsistence,  at  the 
cost  ot  a  vast  change  in  its  natural  habits."  Since  this 
account  was  written  the  change  of  habits  in  question  has 

jlZl  T?!^.^  1^1  ''''°"'  ^^^^^^  ^"  the  sheep-farmers. 
It  appears  that  the  birds  prefer  the  fat  parts  of  the£  victims 
and  have  learnt  to  bore  into  the  abdominal  cavity  straight 
down  upon  the  fat  of  the  kidneys,  thus  of  course  kilHng  the 

Another  case  of  local  variation  of  instinct  is  furnished  by 
the  statement  of  Adamson.  that  in  the  island  of  Sor  rabbits 
do  not  burrow.  This  statement,  however,  although  accepted 
by  Dr.  E.  Darwin,  has  not,  so  far  as  I  know,  been  either  con- 
firmed or  refuted.  But  with  reference  to  variations  in  the 
instinct  of  burrowing,  I  may  allude  with  more  confidence  to 
the  case  given  by  Mr.  Darwin  in  the  Appendix  on  the 


LOCAL  AND  SPECIFIC  VARIETIES  OF  INSTINCT.  249 

authority  of  Dr.  Andrew  Smith,  viz.,  "  that  in  the  uninhabited 
parts  of  South  Africa  the  hyaenas  do  not  live  in  burrows, 
whilst  in  the  inhabited  and  disturbed  parts  they  do.  Several 
mammals  and  birds  usually  inhabit  burrows  made  by  other 
species,  but  when  such  do  not  exist  they  excavate  their  own 
habitations." 

In  "  Animal  Intelligence  "  I  stated,  under  the  authority 
of  Dr.  Newbury's  Eeport  on  the  Zoology  of  Oregon  and 
California,  that  the  beavers  in   those  districts  exhibit  the 
peculiarity  of  never  constructing  dams,  and  seeing  that  the 
building  of  these  structures  may  be  regarded  as  one  of  the 
strongest  instincts    manifested  by  the  species,  I   supposed 
the  failure  of  the  Oregon  and  Californian  beavers  in  mani- 
festmg  this  instinct  to  constitute  a  remarkable  case  of  the 
local  variation  of  instinct.     Professor  Moseley,  however,  who 
has  travelled  in  Oregon,  now  writes  me  that  this  absence  of 
beaver  dams  is  in  his  opinion  due  simply  to  the  severity  with 
which  the  nnimals  are  trapped.     "What  few  beavers  that 
remam  are  too  constantly  liable  to  interruption  to  be  able  to 
construct  dams,  or  for  this  to  be  worth  their  while.    They  thus 
live  a  more  or  less  vagrant  life  about  the  streams."     It  will  be 
observed,  however,  that  Professor  Moseley  speaks  of  "  the 
few  beavers  that  remain,"  whereas  Dr.  Newbury  says  of  the 
same  districts  : — "  We  found  the  beavers  in  numbers  of  which, 
when  applied  to  beavers,  I  had  no  conception."     Therefore' 
I  infer  that  since  the  time  when  Dr.  Newbury's  Pteport  was 
published,  the  number  of  the  beavers  must  have  been  greatly 
reduced  by  trapping.     But  if  so,  at  the  time  when  the  Eeport 
was  pubhshed,  Professor  Moseley's  explanation  of  the  absence 
^  dams  can  scarcely  have  applied  to  the  facts  of  the  case. 
Hence,  I  am  still  disposed  to  think  that  we  have  in  this  case 
an  instance  of  the  local  variation  of  instinct — seeing  that  the 
variation  of  habit  was  remarkable  even  before  the  introduc- 
tion of  the  disturbing  elements  to  which  Professor  Moseley 
now  alludes.      Be  this  as  it  may,  however,  it  is  certain  that 
the  solitary  beavers  of  Europe  present  a  striking  local  varia- 
tion of  instinct,  not  only  in  having  lost  their  social  habits, 
but  also  in  having  ceased  to  build  either  lodges  or  dams. 

The  last  instance  of  the  local  variation  of  instinct  which 

I  have  to  adduce  is  one  which  has  already  attracted  a  good 

deal  of  attention ;  I  refer  to  the  barking  of  dogs.*     The  habit 

•  A  BomewLat  analogous  instance  seems  to  be  supplied  by  the"cat-a' 


^^K  i 


f'        ' 


1! 


250 


MENTAL  EVOLUTION  IN  ANIMALS. 


i!     M 


f  : 


ft'  ,' 


of  barking,  althougn  perhaps  acquired  as  a  result  of  domesti- 
cation    IS  so  innate  and  general  among  most  of  the  breeds 
that  It  deserves  to  be  regarded  as  an  instinct.     Yet  Ulloa 
noticed  that  in  Juan  Fernandez  the  dogs  did  not  attempt  to 
bark  till  taught  to  do  so  by  the  importation  of  somedo-^s 
Irom  Europe— their  first  attempts  being  strange  and  un- 
natural    Linnaeus  records  that  the  dogs  of  South  America 
did  not  bark  at  strangers.      Hancock  says  that  European 
dogs  when  conveyed  to  Guinea  "in  three  or  four  generations 
cease  to  bark  and  only  howl  like  the  dogs  natives  of  that 
coast        Lastly,  it  is   now  well  known  that  the  dogs  of 
Labrador  are  silent  as  to  barking.     So  that  the  habit  of  bark- 
ing, which  IS  so  general  among  domestic  docs  as  to  be  of  the 
nature  of  an  instinct,  is  nevertheless  seen   to  vary  with 
geographical  position.  '' 

Specific  Variations  of  Instinct. 

To  the  above  instances  of  the  local  variations  of  instinct 
I  shall  now  add  a  few  cases  of  what  we  may  caU  specific 
variations  of  mstinct-that  is  to  say,  instincts  which  occur  in 
a  species  of  a  character  strikingly  different  from  the  instincts 
which  occur  m  the  rest  of  the  genus.     After  what  has  been 
said  on  the  local  variations  of  instinct,  the  attesti      value  of 
tlie  cases  which  we  are  about  to  consider  must  be  evident. 
For  we  should  expect  that  if  the  conditions  which  determine 
a  local  variation  of  instinct  are  constant  over  a  sufficient 
lengt  ■  ri  time,  the  variation  should  become  fixed  by  here- 
dity and  so  give  rise  to  a  change  of  instinct  in  the  species 
afiected— which  change  ought  to  become  observable  in  the 
contrast  exhibited  by  the  instincts  of  this  species  and  those 
of  the  rest  of  its  allies.    This  head  of  evidence  becomes  of 
special  value  when  we  remember  that  it  is   the  nearest 
approach  we  can  hope  to  obtain  of  anything  resembling  a 
paheontology  of  instincts.      Instincts,  unlike  structures,  do 
not  occur  in  a  fossil  state,  and  therefore  in  the  course  of  their 
modification  they  do  not  leave  behind  them  any  permanent 
record,  or  tangible  evidence,  of  their  transformatioHs      But 
we  obtain  evidence  of  transformation  almost  as  conclusive  in 
the  cases  to  which  I  now  allude;   for  if  a  living  species 

wallings"  of  cats;    for,  accordinc;  to  Roulin  (quoted  by  Dr.  Carpenter  in 


LOCAL  AND  SPECIFIC  VARIETIES  OF  INSTINCT.  251 

inhabiting  a  certain  restricted  area  exhibits  a  marked  depar- 
ture  irom  the  instincts  elsewhere  characteristic  of  its  cenus 
we  can  scarcely  question  that  the  departure  is  indeed  a 
departuTe~%.e.,  that  originally  the  instincts  were  the  same 
as  those  occurring  in  the  rest  of  the  genus,  but  that  owincr  to 
peculiar  local  conditions,  local  variations  of  instinct  arose 
and  were  continued  till  they  became  hereditary,  and  so  led 
to  Qpartmgaway  of  the  instincts  of  this  species  from  those 
or  its  allies.* 

For  the  sake  of  brevity  I  shall  here  confine  my  instances 
to  those  which  may  be  drawn  from  Birds. 

The  following  concise  statement  of  facts  relating  to  the 
strong  mstinct  of  parasitism  in  the  only  two  genera  oi  birds 
where  it  is  known  to  occur,  is  quoted  from  an  Editorial  note 
m  'Land  and  Water"  (Sep.  7,  1867).  and  displays  very 
remarkable  and  instructive  cross-relations  as  rec^ards  the 
existence  and  absence  of  this  instinct  in  the  sundry  species 
composing  these  two  genera. 

"  The  only  non-cuculine  genus  of  birds  known  up  to  the 
present  time,  which  has  the  habit  of  entrusting  its  e4  to  the 
charge  of  strangers,  is  that  of  the  cow-buntings  (Mdothrus) 
and  the  parasitic  habit  of  M.  pecoris  of  North  America  has 
been  amply  described  by  the  ornithologists  cited  by  our 
correspondent.  There  are  several  other  species  of  this  genus 
and  the  same  parasitic  habit  was  observed  in  another  of  them 
by  Mr.  Darwin.  The  Molothri  are  birds  belonging  to  the 
great  American  family  of  Cassicidce,  which  corresponds  to 
that  of  SturmdcB  m  the  Old  World;  and  they  are  nearly 
akm  to  txie  troopials  (Agelaius).  It  is  remarkable  that  not 
any  ot  the  various  American  Cuculidce  are  parasitic:  whereas 
several  genera  of  this  family  inhabiting  the  major  continent 
and  its  islands,  with  Austraha,  are  now  well  known  to  be  so. 

*  From  the  above  remarks  it  will  appear  that  t  do  not  agree  with 
Mr.  Darwm  in  h>8  view,  expressed  in  the  Appendix,  that  cases  o^spedfio 
variation  of  mstmct  are  difficulties  in  the  way  of  his  theory  of  the  Sal 
development  or  evolution  of  instincts.  On  the  contrary.^for  the  ^na 
given  above,  I  regard  such  cases  as  corroborations  of  ths  theory  2 
source  of  this  diflerence  of  opinion  is,  that  while  Mr.  Darwin  is  Ybove  all 

nZct"l"eTtwf '  "''r^^  f  'T''''''.^  ^^""^^  '^  *^^  formation  of  fn 
instinct,  1  feel  that  to  expect  such  evidence  in  every  case  of  instinct  would 

be  unreasonab  e,  if  not  inconsistent  with  the  tlieoiy  that  innumerabTe  !n 

stincts  owe  their  present  existence  to  the  destruction  through  nau'ialselec. 

tion  01  the  animals  which  presented  them  in  a  lesser  degree  oipexSi)nI 

Khali  recur  to  this  pomt  in  a  future  chapter.  i'oiict.uon.    * 


M 


252 


MENTAL  EVOLUTION  IN  ANIMALS. 


■f  ■    )  ■ 


HI 


!li 


't 


,  ( 1 


Pirst,  there  are  the  very  numerous  species  of  true  Cuculus, 
with    Its  immediate    sub-divisions,    inhabitants    chiefly   of 
Southern  Asia,  Africa,  and  Australia.      Secondly,  the  crfested 
cuckoos  {Coccystes),  exemplified  by  C.  glandarius,  which  is 
common  enough  in  Spain,  and  has  been  known  to  stray  into 
this  country.     This  bird  deposits  its  eggs  in  the  nests  of  mag- 
pies and  crows.     Another  species  (C.  melanoleums),  which  is 
very  common  m  India,  selects  for  this  purpose  the  nests  of  a 
particularly  noisy  and  familiar  group  of  birds  in  that  part  of 
the  world    often  called  'dire-birds'  {Malacocercus) ;  and  as 
the  latter  la,y  a  spotless  blue  egg,  similar  in  colour  to  that  of 
the  hedge-chanter  {Accentoi'  mochilaris)  of  Europe,  the  e^cr  of 
the  particular  cuckoo  which  seeks  their  nests  is  of  a  nearly 
similar  spotless  greenish-blue  colour.    Another  very  common 
Indian  bird  of  this  family  is  the  koel  {Eudynamis  orientalis) 
the  male  of  jiuch  is  coal-black,  with  a  ruby  eye.  and  the 
female  beautifully  speckled.     A  pair,  in  fine  condition,  may 
now  be  seen  m  one  of  the  aviaries  in  the  Zoological  Gardens. 
Ihe  Indian  koel  mvaiably  deposits  its  egg  in  a  crow's  nest, 
and  the  egg  is  not  unlike  that  of  a  crow  in  its  colouring  and 
markings.     Several  other  species  of  koel  inhabit  the  Asiatic 
islands,  and  there  is  one  in  Australia;  and  as  the  koels  are 
not  migratory  birds,  it  follows  that  the  parasitic  habit  is  in- 
dependent of  any  migratory  necessity.      That  extraordinary 
cuculme  bird,  the  Australian  channel-biU  {Scythrops  nmce- 
fioilandia;),  is  known  to  be  parasitic,  for  the  young  have  been 
repeatedly  seen  tended  and  fed  by  birds  of  other  species ;  and 
therefore  it  is  a  lapsus  pennm  on  the  part  of  Mr.  Gould,  in 
his   Handbook  of  the  Birds  of  Australia.'  describing  a  speci- 
men ot  it  as  having  been  an  'incubating  female !"    But  the 
coucals  {Centropus),  very  common  and  conspicuous  birds  in 
bouthern   Asia,  Africa,  and  Australia,  are    not  parasitic  • 
neither,  we  have  reason  to  believe,  are  the  extensive  malkoha 
series  {Fhcenicophaus  and  kindred  genera),  which  inhabit  the 
same  geographical  area.    Among  the  American  Cuculidce,  the 
species  of  Coccyzus  are  nearly  akin  to  the  crested  cuckoos 
{Loccystes)  oi  the  major  continent;  and  these,  like  the^Q,vQ,. 
aitic  Cuculidce,  produce  their  eggs  at  considerable  intervals 
so  that  eggs  and  young  of  different  ages  are  found  in  the 
same  nest ;  while  more  advanced  young,  that  had  quitted  the 
nest,  are  still  fed  by  their  parents  while  keeping  to   the 
immediate  vicinity  of  the  nest;  as  may  likewise  be  observed 


LOCAL  AND  SPECIFIC  VARIETIES  OF  INSTINCT.  253 

of  the  screech-owls  (>S<m,  as  now  limited).     In  the  ani 
{Crotophaga),  which  have  much  in  common  with  the  coucals 
of  the  major  continent,  while  in  other  respects  their  habits 
are  very  pecubar  for  birds  of  this  family,  'an  immense  ne? 
of  basket-work '  is  formed  by  the  united  labours  o^a  flock  of 
them,  usually  on  a  high  tree,  where  'many  parents  brine, 
torth  and   educate  a  common  family.'      Mr  Eichard  Hilf 
whose  statements  in  Jamaican   ornithology  are  worthy  of 
unlimited   confidence,  writes   Mr.  Gosse,  observes  :    '  Some 
half-dozen  of  them  together  build  but  one  nest,  which  is  lar^e 
and  capacious  enough  for  them  to  resort  to  in  common  and 
to  rear  their  young  ones  together.'      All  of  these  divers'ified 
tacts  must  be  borne  in  mmd  by  naturalists  who  would  try  to 
assign  a  reason  for  the  parasitic  habits  of  various  Cmulidw,  as 
also  those  of  the 'cow-buntings,'  which  have  no  other  trait  in 
common  with  the  parasitic  genera  of  Cncnlidccr 

Ihe  Upland  Goose  of  South  America  furnishes  an  admir- 
able  case  of  a  fixed  specific  variation  of  instinct.  These  birdq 
are  true  geese  with  well  webbed  feet;  yet  they  never  enter 
the  water  except  perhaps  for  a  short  time  after  hatchincr  their 

S  ^^^\^^%  ^"-'P  ^"^  ^^"  protection  of  their  youn^! 
Similarly,  Mr.  Darwin^  MS  says  of  the  Upland  Geese  of 
Australia,  which  also  have  well  webbed  feet,  that  "thev  are 
long-legged,  run  like  gallinaceous  bixds.  and  seldom  or  never 
enter  the  water:  Mr.  Gould  informs  me  that  he  believes  they 
are  perfectly  terrestrial,  and  I  am  told  that  at  the  Zoological 
Gardens  these  birds  and  the  Sandwich  Islands  Goose  reeni 
quite  awkward  in  t^ie  water."    The  MS  also  points  out  thS 
"the  long-legged  Flamingo  likewise  has  webbed  feet    yet 
hves  on  marshes,  and  is  said  seldom  even  to  wade  except  in 
very  shallow  water.     The  Frigate  bird  with  its  extreme  y 
short  legs  never  ahghts  on  the  water,  but  picks  up  its  prey 
iTl-^  K  ""t  ^f"  wondrous  skill;  yet  its  four  toes  are  all 

united  by  a  web;  the  web.  however,  is  considerably  hollowed 
out  between  the  toes,  and  so  tends  to  be  rudimentary. 

"  9n  the  other  hand,  there  does  not  exist  a  more  thoroufvhlv 
aquatic  bird  than  the  Grebe,  but  its  toes  are  only  widely 
bordered  by  membrane.  The  water-hen  maybe  constantly 
seen  swimming  about  and  diving  with  perfect  ease  •  yet  its 
long  toes  are  bordered  by  the  merest  fringe  of  membrane. 
Other  closely  allied  birds  belonging  to  the  genera  Cm-  Passa 
&c.,  can  swim  well,  and  yet  have  scarcely  any  traces  of  web- 


l!ri;j 


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/!•• 


254 


MENTAL  EVOLUTION  IN  ANIMALS. 


moreover  their  extremely  long  toes  seem  admirably  adapted 
to  walk  over  the  softest  swamps  and  floating  plants:  yet  the 
common  corncrake  belongs  to  one  of  these  very  genera,  and 
havmg  the  same  structure  of  feet,  haunts  meadows,  and  is 
scarcely  more  aquatic  than  a  quail  or  partridf^e  " 

The  MS  goes  on  to  detaU  other  and  analogous  cases,  such 
as  that  of  the  Ground-woodpecker,  Ground-parrots,  and 
Iree-frogs,  which  have  abandoned  their  arboreal  habits;  in 
all  which  cases  tlie  generic  stmctures  specially  adapted  to 
arboreal  habits  remain.  Similarly  the  swallow-tailed  Hawk 
IS  mentioned  as  catching  flies  on  the  wing  like  a  swallow, 

fi,  t'^T  ^^°'^  T'?  "^^^  ^^  birds  "-which  has  assumed 
the  habits  of  an  Auk ;  the  Water-ouzel,  a  menJDer  of  the 
Thrush  family,  which  runs  along  the  bottom  of  streams 
using  itfi  wings  for  diving  and  its  feet  for  grasping  stones 
under  tlie  water,  "and  yet  the  keenest  observer  coufd  never 
have  foretold  this  singular  manner  of  life  from  the  most 
careful  examination  of  its  structure," 

All  the  above  cases  are  given  by  Mr.  Darwin,  not  in  re- 
lation to  Instinct  but  to  enforce  his  argument  on  adaptive 
structures  being  developed  by  natural  selection  instead  of 
designed  m  special  creation.      But  I  have  used  them  in 
relation  to  the  development  of  Instinct,  because,  if  we  already 
uelieve  m  the  natural  evolution  of  organic  structures  such 
cases  as  these  afford  the  best  possible  evidence  of  the  varia- 
aon  of  mstmct.     As  evolutionists  we  could  have  no  strono-er 
testimony  to  the  previous  though  now  obsolete  instincts  of  a 
species,  than  that  which  is  supplied  by  the  presence  of  pecu- 
liar though  useless  structures  which  in  allied  species  are 
correlated  with  particular  instincts.     For  we  must  always  re- 
member, as  previously  observed,  that  instincts  are  never  like 
structures,  fossilized,  and  therefore  that  we  can  never  obtain 
direct  historical  evidence  of  their  transmutation.     But  the 
best  substitute  for  this  evidence  is,  I  think,  such  testimony 
a^  I  have  adduced  of  persisting  structm.y  pointing  to  obsolete 
instincts.      Similar  evidence  in  kind,  though  not  quite  so 
strong  in  degree,  is  furnished  by  cases  in  which  one  species 
ot  a  genus,  or  one  genus  in  a  family,  exhibits  an  instinct 
peculiar  to  that  species  or  genus— i.e.,  cases  in  which  the 
instinct  does  not  occur  in  aUied  species  and  genera-  for  this 
shows,  if  we  already  accept  the  doctrine  of  the  transmutation 
ot  species,  that  the  peculiar  instinct  must  have  arisen  in  the 


IS 


LOCAL  AND  SPECIFIC  VARIETIES  OF  TNSTINCT.  255 

particular  species  or  genus  in  question,  after  that  species  or 
genus  had  branched  off  from  the  more  ancestral  yp^e     Now 
such  cases  of  specific  instinct  are  by  no  means  ra^e-caseT 
I  mean,  like  that  of  the  Californian  Woodpecker    J/irS 
fovmxcxv<y,^UB\  which  displays  the  curiously  distinctive  Set 
of  stonng  acorns  in  the  crevices  of  the  bark  of  IheTeLlow 
Y^n.{PxnusvoncUrom)  for  future  food,  while  no  otl   r  s^e  ?el 
of  «roodpecker  shows  any  tendency  to  such  a  habit*     S 
such  cases  of  instinct  peculiar  to  one  species  or  genus  are   o 
common  that  I  feel  it  would  be  needless  to  enumera  e  them 
in  view  of  the  more  conclusive  cases  just  given-cases  m^^^^ 
conclusive  because  the  obsolete  instincts  happen  to  have  been 
of  a  kind   requmug  special  corporeal   structures   for  tS 
operation,  which  now  survive  tJieir  ancestral  uses  t    Las  1^ 
we  must  not  forget  the  important  fact  that  we  are  far  from 
being  wholly  without  evidence  of  the  transmutation  oflnsinct 
taking  place  under  actual  observation-as  in  the  case  of  th« 
dudes  in  Ceylon  having  quite  lost  their  naturaUnst  nets 
with  regard  to  water  (in  this  resembling  the  upland  4se) 
sparrows  and  swallows  building  on  houses  instead  of  on  ?rees 
insects,  birds  and  mammals  which  normally  feed  on  vegetabk 
substances  suddenly  becoming  carnivorous,  &c.,  &c;  for  all 
these  cases  of  /.m^  varieties  of  instinct  are  redly   o  manv 
cases  of  moza/ varieties,  and  the  step  between  this  and  .S 
varieties  is  clearly  not  a  large  one.  "^    •'^ 

ot^-f '^°''^'"^  *°  ^''-  C.  J.  Jack8on  iProc.  Boston  Nat   TTl.f   «„„        i 

conditions  of  life,  and  WMtoS  ?l.  ..1.        '.■''""S  ."''*'  ""*""' 
instance,  « in  all  iS^rfof^ta  ToSe^LT'of'Tn  I  '""?•     ^''"■'  '^ 

in,p,i«.ning  their  bene  in  LCoTS™  th  pTast.T:  £"         '°'"°°'  °' 


III 


ill.:! 


% 

ill 


256 


MENTAL  EVOLUTION  IN  ANIMALS. 


CIIAiTER  XVIL 

Instinct  (continued). 

Examination  of  the  Theories  of  o'ihlu  Writers  on  thb 
Evolution  of  Instinct,  with  a  General  Summary  of 
THE  Theory  here  Set  Forth. 


jf*.  4 


.i' 


'  ( 


1-^ 


ft 


Mill,    fiom    ignoring   the  broad  facts  of  heredity  in    the 
region  of  psychology,  may  be  said  to  deserve  no  hearing  on 
the  subject  of  instinct ;  and  the  same,  though  in   a  lesser 
degree,  is  to  be  remarked  of  Bain.     Herbert  Spencer,  and  his 
expositor  Fiske,  express  with  strong  insistence  the  view  that 
natural  selection  has  been  of  very  subordinate  importance  as 
an  evolving  source   of  instinct.     Lewes   virtually  ignores 
natural  selection  altogether,  but  nevertheless  is  not  in  agree- 
ment with  Spencer,  inasmuch  as  Spencer  regards  instinct  as 
*'  compound  reflex  action,"  and  the  precursor  of  intelligence, 
while,  as  we  have  already  seen,  Lewes  regards  it  as  "  lapsed 
intelligence,"  and  therefore  necessarily  the  successor  of  in- 
telligence.   Thus,  while  Lewes  maintains  that  all  instincts 
must  originally  have    been   intelligent,   Spencer  maintains 
that  no  instinct  need  ever  have  been  intelligent.*      The 
deliverance  of   Darwin  upon  this  subject  I  shall  render 
bye-and-by. 

The  position  of  Mr.  Spencer  is  severely  logical,  and  this 
renders  easy  the  definition  of  the  points  wherein  I  here  dis- 
agree with  him.  His  argument  is  that  instinctive  actions 
grow  out  of  reflex,  and  in  turn  pass  into  intelligent  actions, 
so  that  in  his  terminology  an  instinctive  action  need  never 
have  been  intelligent,  and  an  intelligent  action  need  never 
become  instinctive.  He  is  express  in  saying  that  although 
**  in  its  higher  forms,  Instinct  is  probably  accompanied  by  a 

*  I.e.,  no  true  instinctive  action  occurring  in  all  individuals  of  a  species  j 
he  recognizes  the  principle  of  lapsing  intelligence  in  individuals. 


EXAMINATION  OP  THE  THEORIES  OF  OTHER  WRITERS.      257 

rudimentary  consciousness,"  nevertheless   thi^  or...oni 

IS  not  essential  to  the  formation  ofthrLtiictb,.".?' 

^c^'^'ir  'T  ^'  ^^^g-winrcrpSt/ofc  t 

stinct—  the  quick   success  on   of  changes   in   «    Jiii,- 
implying  as  it  does  pei^etual  experLncel  of  diffLt^^^^^^^^ 
likenesses,  constitutes  the  raw  matPrinl  nf  "'"^^^"^^^  '^"^ 

the  implication  is  that  as%a;7as"n1S  if  d^veW 
kind  of  consciousness  becomes  nascent"        ''^^^^^P^^'  «^«^« 

this^tr^cS  Tuc^t^irin^d^^^^^^^^^^^^  ''T'  ^'-1 
value  in  relation  to  the 'StlopTntt  o  VoliouteT-i 
appears  to  me  impossible  to  obtain  by  it  a  compS  x.W 

Cknd  ^h?  hT;;""^  ''  ^"^^^"^^-     MultituZ  of  fa^    "of 
mnv  of  fl  l"    K  ^^y\?'''^''  "^-^y  te  rendered  to  prove  th^t 

eith^er  the  extr^^ierf^L^er^^^^^^ 
fZT  T^  ZT  «°^««i«««ness  as  a  factor  in  the  SaS^n  of 
nstinct,  or  the  extreme  antithetical  view  of  Lewes    which 
gnores  reflex  action  with  natural  selection  as  other  factor    n 
the  process  ;  I  should  feel  less  difficulty  in  choosin  '  he  iSter 
than  the  former     Not  only  do  many  of  thrhSr  i„stW^^ 
hSorv  rr^  '"'^.'"f  '^  ^^""^"S  been  at  some  pfrLd  of  he  ' 
the..^,f^'"!^  by  intelligence,  and  not  only  do  manyof 
these  higher  instincts    now  show  themselves  to  he  nW?o 
under  an  admixture  with  "a  little  dose  of  judgment '  b^uttha 
examples  of  instinct  which  are  chosen  b^M^r    Spencer  .re 

rhlf^'^^fPf  ^^"^'  ^^^°^P^^«  «f  instinct  at  all^  Thev  are 
chosen  as  i  lustrations  because  they  are  the  simp  est  raZ.n1 

a"ctn"i7ho"^'^  '^"^'  ^"^'^^^*'  ^^^  so  h^nS  :f  tr  eflei 
fiS  fh'of  ^Y  ^'''^''  ^^  P''^"'^  ^  e^a^^ine  any  of  them   we 

elabor^fp     ^^  '''  """^  ^.'^'  ^"'^^"^^«'  b^*^  «^«es  of  moreTr'le^s 
elaborate  neuro-muscular  adjustment,  or,  in  his  own  word, 
of     compound  reflex  action!"    And 'the 'fact  that  he  dXnes 
or  "describes"  instinct  as  compound  reflex  Roft^ri^l      I 
carry  n,f, hat  his  doctrine'  Too^rtt    tZllZTe 

spade  is  futile;  the  question  consists  in  the  validity  of  the 
definition.  Now  it  is  ust  because  we  cannot  draw  a  1  ne 
between  simple  reflex  action  and  "  compound  reflex  action  » 

tive,  that  I  have  drawn   the    line  at  consciousness,  and 


m 

Am 


rU 


i:l! 


I' 

';  '^f 

'1 

i  ; 

■  1 

(ill 

d 

258 


MENTAL  EVOLUTION  IN  ANIMALS. 


11) '"   ■ 


denominate  all  actions  which  occur  below  this  lino  (howsoevw 
compound)  reflex,  while  reservinf?  tlie  term  instinctive  for 
habitual  actions  (howsoever  simple)  into  which  there  enters 
this  element  of  consciousness.  And  in  doing  this  I  feel 
certain  that  I  am  not  merely  imparting  clearness  to  our 
classihcation,  but  also  following  the  dimly  intended  meaning 
ot  the  term  instinct  as  ordinarily  used.  No  one  thinks  of 
sneezing,  or  of  tlie  convulsions  produced  by  ticklin",  as 
examples  of  instinctive  actions ;  yet  they  are  "  compound 
reflex  actions"  to  a  degree  of  compounding  not  easily 
paralleled,  and  certainly  much  more  so  than  any  of  the  nou- 
Ijsychical  adjustments  which  are  given  by  Mr.  Spencer  as 
illustrations  of  instinct. 

These  illustrations  have  reference  to  polyps  and  creatures 
witli  rudimentary  eyes,   wherein  the   reactions   to   stimuli 
described  appear  to  me,  as  I  have  said,  in  no  way  to  deserve 
to  be  called  instinctive.     For  instance,  he  shows  how  it  is 
possible  that  without  survival  of  the  fittest  and  without 
intelligent    adjustment,   "psychical  states  being  habitually 
connected,    must,    by  repetition    in    countless   generations 
become  so  coherent  that  the  special  visual  impression  will 
directly  call  lorth  the  muscular  actions  by  which  prey  is 
seized.     Eventually,  the  sight  of  a  small  object  in  front  will 
cause  the  various  motions  requisite  for  the  capture  of  prey." 
But  even  in  this,  the  most  extreme  case  supposed,  if  there  ia 
not  and  never  has  been  any  consciousness  concerned,  the 
complex    adjustment  is  in  no  way  distinguishable  from  a 
reflex  action.     When  I  observed  jelly-fish  crowding  into  the 
path  of  a  sunbeam  shining  through  a  darkened  tank,  and  saw 
that  they  did  so  in  order  to  follow  the  crustaceans  on  which 
tliey  feed  and  which  always  seek  the  light,  I  described  the  case 
as  one  ot  reflex  action,  the  development  of  which  had  no  doubt 
been  largely  assisted  by  natural  selection ;  and  I  should  still 
regard  it  as  a  misnomer  to  call  it  a  case  of  instinct.     For,  on 
the  one  hand,  such  cases  are  not  nearly  so  complex  in  the 
neuro-muscular  machinery  which  they  betoken  as  are  many 
or  most  of  the  reflex  actions  exhibited  by  the  higher  animals 
and,  on  the  other  hand,  if  we  were  to  call  them  instincts,  so 
also  should  we  require  to  call  every  other  case  of  reflex  action. 
It  is,  indeed,  impossible,  as  I  said  at  the  commencement  of 
these  chapters  on  Instinct,  always  in  particular  cases  to  draw 
the  line  between  instinct  and  reflex  action ;  but,  as  I  like- 


f 


our 


EXAMINATION   OP  THE  THEORIES  OF  OTHER   WRITERS.      259 

Wise  said,  "this  is  altogether  a  separate  matter"  and  has 
nothing  to  do  witfi  dohning  what  instinct  is.  An.l  certainly 
as  I  tiiere  showed,  instinct  is  something  more  than  reflex 
action  ;  "  there  is  in  it  the  element  of  mind." 

Moreover,  if  we  were  to  classify  t.iese  and  aU  other  cases 
ot  still  more  compound  reflex  action  under  the  designation  of 
instinct  there  would  be  no  category  left  in  which  to  place  all 
cases  ot  true  instinct,  i.e.,  cases  where  consciousness  is  necessary 
to  the  perlormauce  of  an  action  which  but  for  the  occurrence  of 
consciousness  would  be  properly  classified  as  a  reflex  action 
Ut  course  if  we  choose  we  may  altogether  ignore  the  distinct 
tion  which  the  occurrence  of  consciousness   in   an   action 
imposes,  aiK    so  classify  all  redex  actions  and  all  instinctive 
actions    under  one  denomination;    but  this   is    not  what 
Mr.  Spencer  professes  to  do.     He  draws  a  distinction  between 
reflex  action  and  instinct ;  but  he  does  not  draw  it  at  con- 
sciousness; and  the  result  is  that  while  no  real  distinction  is 
drawn  between  the  two  (for  compound  reflex  action  is  still 
notfiing  more  than  a  mechanical  advance  upon  simple  reflex 
action),  the  great  distinction  which  actually  exists  is  i<mored 
Let  us  take  an  illustration.     The  giving  of  suck  to  youna  by 
mammals  must  be  regarded  as  a  truly  instinctive  act    Why  ? 
1  answer,  for  one  reason,  because  the  animal  which  performa 
tfie  action  is  conscious  of  performing  it.     If,  on  the  other 
hand,  the  young  animal  which  is  taking  the  suck  is  too  youncr 
(as  in  the  case  of  the  Kangaroo)  to  be  reasonably  supposed 
conscious  of  performing  its  part  in  the  process,  I  should  say 
that  the  action  of  the  young  animal  is  to  be  regartled  as  reflex 
liut  Mr.  Spencer  would  classify  both  these  actions  under  the 
common  designation  of  instinctive.     Suppose,  then,  that  this 
IS  done  and  what  should  we  say  to  this  case  from  among  the 
polyps  ?     McCready  describes  a  species  of  Medusa  which 
carries  its  larvte  on  the  inner  side  of  its  bell-like  body     The 
mouth   and  stomach  of  the  Medusa  hang  down  like   the 
tongue  of  a  bell,  and  contain  the  nutrient  fhiids.     McCready 
observed  this  depending  organ  to  be  moved  first  to  one  side 
and  then  to  the  other  side  of  the  bell,  in  order  to  give  suck 
to  the  larvae  on  the  sides  of  the  bell-the  larvie  dippin-  their 
long  noses  into  the  nutrient  fluids  which  that  oi™  of  the 
parents  body  contained.     Now  if  this  case  occurred  in  any 
ot  the  higher  ammals,  where  we  might  suppose  intelligent 
consciousness  of  its  occurrence  to  be  present  it  would  pro- 


;'   It      ' 


!;:f 


^1 


*  ■  ;  1 

,  ^ 

■  1;. 

'i 
Ma 

■  j 

260 


MENTAL  ETOLUTIOlf  IN  ANIMALS. 


wa„antedSrJrj„g  t';,tenlVKV  "^"'=  ""' 
tion  of  the  procesq  anH  fi  w       •  •"  intelligent  pereep- 

i.s-a^si:SH~S^S3 

or  a  mammal     Si.rplv  if  io  „  ^       ^i  v  *=       ^  *^  ''"^  case 
makes  between  two  such  LS^^lTilf      Pfc^ieal  element 

guish  the  most  essential  S,J^„nL\inct    It*  '"  ■^"''- 

these  it  is  not  the  chief  causp  »•     L,    •!      v.      ^  ^^^^^  ^'^^ 

selection  amonc.  vild  anim«l^^    «"^   ^^^      ^^""^  ^      "^^""'^^ 
and  fcfieve.  would  never  h^^tZe  iL^Sir-S 

•  I'nncij^let  of  Psychology,  i,  p.  423. 


V 


EXAMINATION  OF  THE  THEOKIES  OP  OTHER  WRITERS.   261 

even  as  regards  the  instincts  of  wild  animals  flip  in^^    ^  • 
question  appears  to  me  no  less   ob]  S^nablV"^^^^ 

Still,  having  thus  shown  as  clearlv  as  T  rnn  fi^of  • 
covering  another  consideration  whichioTthe  sake  T'^^'" 

Tt  d  T  l^l^'^^^-^  P^^^ 

natural  selection  «n/nfi^  •^"''  independently  both  of 
equilibratt">X:f hel^^^^^^^^^  .^^    "direct 

out  of  reflex  action      T?nw^?ifl      u      ^^f""''®  immediately 

mind-element  arosp  anrl  if  a,^  t\t     o  ,  -^  ^  which  the 

present  a  PossiTthX  d"  i^ifcK^t  ST'"*  T 
instincts— or  instincts  nf  fi.o  i^  7  ^  ?*  *^®  simpler 
taken  origin  T  s  thi?d  mnH  ^^^^^.^J^^als-may  have 
converse  ^r  oppo  te  of  t^at  wb-'l^^  be  observed,  is  the 
lapsing  of  intellSce-  it  i«  f  /^  we  have  called  the 
cuLnates  in  coS^^^^^^  «P  to.  or 

ceases  to  be  reflex  and  Wnn!.  •  f-.x  *^'^^®  ^he  action 
sce„di„«  „.  bet^^de  SUol^Slo  rS*  "Lf 
that  such  a  process  may  take  place  is  I  tbinV  ^f  Ji  ■'■ 
grounds  very  probable,  although^  fro  AL  t^^i^^^^^^^^  f/'^''^ 
It  IS  not  possible  to  find  proof  1,f  itsTcc^e    for  ifif  7'' 

cipiently  pre  enf  ThpJ  1        ?1  ^^^s^io^sness  even  if  in- 


'III 


f|;  .^•'i' 


|i  it 
a  iii 


,«'! 


iil      '1!; 

■  \ 


Ml-  ; 

J.  f 

'■  >  I' 


1  s'u 

f 

' :  l-y 

''!;. 

r' 

■j 

;   'i 

;.  ■  i, 

■  Mi 

I  1  ' 

:''■ 

262 


MENTAL  EVOLUTION  IN  ANIMALS. 


ir 


h:i    , 


mnH^I'^"  *!!^  /^^S'^  ^""^  *^^  instinctive,  this  possible  third 
mode  in  which  rudimentary  instincts  may  arise  need  not  cla  m 

fmnlr  ^^^^°"^^  f^^  subject  IS,  as  we  have  seen,  of  much 
importance  m  relation  to  the  origin  of  consciousness 

It  only  remains  to  point  out  that  if  instincts  ever  do 

nirir'T'  ''^''^r^^'^t  -plication  wouldTpea? 
must  « W«\^''''''  admits,  that  "survival  of  the  fittest 
must  always  be  a  co-operating  cause."  I  should,  however 
even  here  be  inclined  to  go  further,  and  to  say  that  survTval 
of  the  fittest  must  m  this  co-operation  be  of  more  than  the 
subordinate  importance  which  Mr.  Spencer  attributes  ?o  it 

fCCl^rV^'''^  "S"^°,'^^  '^'^  «^  '^'^  Medusa  seeking 
the  light,  and  supposing  the  action  to  have  become  dimly 

t^s::^tL'll!^"fr"'^'°^*^"^^^^^  ^^^^^^^^  ^^-^^y 

to  seek  the  light  first  began  to  manifest  itself,  and  the  indi- 
viduals which  sought  the  light  were  therebv  enabled  to  nro 

SdTonc:!'''^  'H"'^?  ^^^  not," natural  sd'ecK 
would  at  once  begin  to  develop  the  reflex  association  between 
luminous  stmitdation  and  movement  towards  light.     HerTin 

brSina'v^'f  "^'"'^"^  "^  ^7  ''^''  ^^"««  «f  ^  directly  equii^ 
bratmg  kind  seems  out  of  the  question,  inasmuch  L  apart 

couTdKor>T'''-^^;'^  ^  '^^^^^^^-'  i«  absent' there 
light  and  the  obtainmg  of  food  in  the  light.  Only  by  natural 
selection  could  such  a  bond  hav.  here  been  established  and 
the  same  considerations  apply  to  many  or  most  of  the  Quas:U 
instinctive  actions  exhibited  by  low  animals.  ^ 

bo  much  then  for  the  view  which  would  regard  aU  in- 
s  incts  as  outgrowths  of  reflex  action.  But  scarcely  less 
objectionable  is  the  other  extreme  view  which  woS  rec/aS 
all  instincts  as  outgrowths  of  intelligence.     This  as  I  have 

tne  Duke  of  Argyll,  who  seems  never  to  have  read  Mr 

S  eXn*  Bu?r' '!i'  ^rtP"^-^  of  instincts  by Taturai 
selection.*  But  be  individual  opinion  what  it  may  surely  it 
IS  suftici^ntly  evident,  as  pointed  out  at  the  commencernent 
of  our  discussion,  that  to  assign  aU  instincts  to  an  inSent 


(    ( 


EXAHIINATION  OP  THE  THEORIES  OF  OTHER  WRITERS.      263 

on^fhil^lT^r.^*^'"'^*,^*  ^.^^^°«  ^  ^^lid  explanation  of 
one  thing  a  satisfactory  explanation  of  another 

,.^f^''''i''''^'''S.  then,  in  the  light  of  all  the  foregoincr  facts 
both  the  principles  Avhich  are  concerned  in  the  development' 

Ba^^r  """^  P*''  ^"^  ^"^  '^'^'  ^^"  opinion  of  Mr. 

In  the  «  Origin  of  Species  "  he  writes  (pp.  206-7^   "  Tt 

p?n'h?T  ^^^^,^^itf  1  action  to  become  inherited-and  it 

can  be  shown  that  this  does  sometimes  happen-then  the 

Sot  l''  ^''^''"^  7^^^  '"'S^'^^^y  ^^«  ^  habit  and  an 
Mnl..f  •  TT/^i  '^.°'"  ^^  ^°*  *«  h«  distinguished.  If 
Mozart,  instead  of  playing  the  pianoforte  at  thrle  years  old 
with  wonderfully  little  practice,  had  played  a  tune  with  no 
practice  at  all,  he  might  truly  be  said  to  have  done  so  instinc- 
tively.* But  It  would  be  a  serious  error  to  suppose  that  the 
greater  number  of  instincts  have  been  acquired  by  habit  in 
one  generation,  and  then  transmitted  by  i^eritance  to  sue 
ceeding  generations.     It  can  be  clearly  shown  that  the  most 

rbnf'1'1.'"?^"''?^^'^  ^^''^  ^«  are  acquaLted  namely 
those  of  the  hive-bee  and  of  many  ants,  could  not  posS 
have  been  acquired  by  habit.  possiDiy 

.      "  It  will  be  universally  admitted  that  instincts  are  as 
important  as  corporeal  structures  for  the  welfare  of  each 
species,  under  its  present  conditions  of  life.     Under  chanS 
conditions  of  life,  it  is  at  least  possible  that  slight  modla^ 
en.   r^'^^'i  f  «^'-  ^'  P^^^^^^l^  '^  ^  species    Tnd  tfit 
see  .n%  r^^u*^^*  '^'^"'1^  ^"  ^^^^  ^^^^  ««  little,  then  I  can 
see  no  difficulty  in  natural  selection  preserving  and  continu- 
ally  accumulating  variations  of  instinct  to  aSy  extent    hat 
was  profitable     It  is  thus,  I  believe,  that  all  the  more  com- 
plex  and  wonderful  instincts  have  Originated.    As  modSl 
usenr  b«V?'''^^  structures  arise  from^  and  are  increased  by, 
noHoubt    'htl'''  ^^T^^i'^hed  or  lost  by  disuse,  so  I  d^o 
effltrnf  hk  f    ''•''  ""'^^  '^'^'"'^'-    ^^<^  I  ^^elieve  that  the 
to   the  Pfftt    T  't  "^r^  r^'^  °^  subordinate  importance 
to   ihe  effects  of  natural  selection  of  what  may  be  called 
spontaneous  variations  of   instincts  ;_that  is  of^ariattlns 


,.'r  i;r 


1 1 


f ' 

1 

i 

'  ■•.r  ; 

n^ 


264 


MENTAL  EVOLUTION  IN  ANIMALS. 


produced  by  the  same  unknown  causes  which  produce  slicrht 
deviation  of  bodily  structure."  proauce  siigiit 

Again  in  the  "Descent  of  Man,"  he  repeats  substantiflllv 
the  same  judgment  (pp.  67-8);  and  among  h  MSsTfin^ 
the  following  passage,  which  I  shaU  quote  because  it  serves  to 

"  iuK^^^^^  ^'^"r^^  t'^^^^  emphatic  manner 

Altliough,  as  I  have  attempted  to  show  there  is  a  strik- 
ing and  close  paraUelism  between  habits  and  instincts    Ind 
a  hough  habitual  actions  and  states  of  min^do  hecome  here^ 
di  ary,  and  may  then,  as  far  as  I  can  see,  most  Tronerlv  be 
called  instinctive;  yet  it  would  be,  I  beCe   the  Stest 

ZlX  ^k\''  fl  ^''''  ^-Jo^ity  of  instincts  as  Sred 
through  habit  and  become  hereditary.     I  believe  fW  rnlf 

tion,  of  shght  and  profitable  modifications  of  other  instS- 
which  modifications  I  look  at  as  due  to  the  same  causes 
which  produce  variations  in  corporeal  structure  Indeed  I 
suppose  that  it  will  hardly  be  doubted,  when  an  ins^rnctiVe 

strengthened  and  perfected  by  habit;  just  in  the  samd 
manner  as  we  may  select  corporeal  structures  ^onducin'^o 
fleetness  of  pace,  but  likewise  improve  this  quality  by  train^ 
ing  in  each  generation."  lu^xiuy  uy  craiu- 

From   these  quotations  it  is  evident  that  Mr  Darwin 

SclfonTfo?'  ?°''  ''^  ''^''^^''  intelligence  and  nat^S 
selection  as  operating  causes  in  the  formation  of  instinct 
but  that  he  regarded  natural  selection  as  the  more  impor  ant 
of  the  two     Although,  however,  he  does  not  exp  Sslv  say 
so  I  cannot  doubt-in  fact  I  know-that  he  fuUy Seized 

inVu7h:f  Sr  fo?^^^^^^^^       in  supplying  adap'tivT^dt 
iin  uisnea  Horn  fortuitous  variations  to  be  seized  unon  hv 
natural  selection.     Viewed  in  this  relation,  natural  se^^ction 
may  be  deemed  a  promoting  cause  of  the   apsin-r  of  L'^m 
gence  in  3  mstinct,  and  the  two  principles  workin'  in  con 

'aC  B^ff'l  '''"''  l^r''  P-^-'than  eiS  iorkh " 
alonj.  But  if  I  were  asked  which  of  the  two  I  deem  morP 
important,  I  should  say  that  natural  selection  must  be  Lw  to 


slight 

itiall)' 

[  find 

ves  to 

mner. 

strik- 

;  and 

here- 

ly  be 

3atest 

Hired 

most 

3elec- 

ncts ; 

auses 

ied.  I 

ctive 

lified 

I  the 

gical 

a  any 

d  in 

been 

same 

g  to 

:ain- 


ural 
net; 
tant 
say 
zed 
dis- 
by 
"ion 

!lli- 

on- 
ing 
ore 
[to 


;      I'' 


, 

■,        ;j 

s 

1 

!i       *■ 

( 

t  ;  ,r 

:r:( 


n 


m  ■ 


'h 


iMM 


Ml 


i  i' 


"e-  r  L  sx 


A  r:  r  I  o  H  . 


I  f.TELLI  C  [  K 


'"        f.    C  T  I  O   N 


EXAMINATION  OP  THE  THEORIES  OP  OTHER  WRITERS.      265 

tion  of  all  the  reasons  whicTlTave  now  ^t^^^^^^  T^^T 
truest  judgment-and  this  without  referTncPtn  Vl«  *^^ 
proachable  authority  upon  the  subierf  wS  ?v  •  u  v^""  '"''^P' 
held  to  speak.  ^      ^^^^  ^^^^^  ^^  must  be 

General  Summary  on  Instinct. 

instincts)  are  able  to  .nrin^     w  ^^,  ""^  definition  of 

senfpH  flot?     u-  P   "°-     ^®^"®  a^icl  there  i  have  renre- 

thaffnllvflV^      !"  important  additional   priinmle    viz 
circumstances  leading  to  an  ^n^lZ^J^J^^ 

ants,  are  sterile.     Lewes  can  neVer  havo  W  .^'■'''^*''l'.    ^^^  '^'^o^g  bees  and 
his  mind,  for  it  proves  his  theory  Slamlnl      r,'^.'''^^^'  '^^^'^  Presented  to 
It  is  hkewise  ineompatible  with  VncS"  Lo^'^^'^m''^'' "^^^^ 
writes :-"  The  automatic  actions  of  a  hi  K°^-        ''"''  ^*''"  »°»tance,  ho 

ans^ver  to  outer  relations  so  ciantlvexnPviJ".?  f?  °^  ^*«  ^"^^  ''^^l^. 
organically  remembered  "  (PW«S/?v  o^P.^'T'^"^'^  ""'*/''7  ^'••^'  '^^  i*  *ere 
as  Lewes  also  forgot,  that^Se  nS  ^hfchtlf"^^'  ''F{  ^*'^-  ^"*  ^'  ^°'SetB' 
has  not  thus  "constantly  expLienced"     -  ''^^  automatic  actions 

perfonning  these  actior.f  betbreirhas  itseff  T^""  ""'^^'T''  f"'"  i*  begins  by 
cell-makinl.  and  u-itliout  its  mrents  ev«  hLw  I*""/  "^'^"'"^"^l  experience  of 
In  the  whole  range  of  instiJct'^o  m.  ^  unZiii'lIC":-'^'  '^-porU^ce. 
been  chosen  by  iVIr    Snenc.T      .in^^ih^  u'wrtunate  illustration  could  have 


ifii 


ill! 


fl^li 


ji   111 


266 


MENTAL  EVOLUTION  IN  ANIMALS. 


ki. 


I  have  ilned  the  ttoZX  t^^^^^^^^^^  ^^^'^Y' 

order  to  represent  the  farf-  Hiof  f  f^^r'^^  ^^  their  summits  in 
adaptation^  or  primLvLrl  ^°*^^>°t  and  non-inteUigent 
together  and  then  possess  a  Z''''^  ^"■^'^"^'^'  ^^^  f"«e 
^  further  growth.  I  have  To  t  '  ""?".  '^P  °^  P^^^'^^P^e  of 
the  two  sides  of  the  dia^  Sr''^'^'^  ""^°^  ^^^ween 
place  at  one  othe^po  nS/  i^'^  and  secondary,  to  take 
Instinct  and  the  brSlSl,     ?v    *^^  ^"^^^^  ^""^''^ry 

Instinct.    I  do  this  trbri„?o\  tS  ^'"  '^  ^''°^^''^  ' 

fact  that  when  once  a  noni?ii-"  V^'°°«.''P"°^in^  the 
been  formed,  it  is  most  readv  tn^n^  *vT  ^T^'^^  '""'^^^^  has 
by  the  principle  oHnteSetn^^^^^ 
principle  is,  as  it  were,  ^bHr  LtZf^'.  ^^^^^^  '^'' 
into  secondary  instinct  PmfV^!  /^-^  ^""^^  ^^^  ^o^en 
remember  is  that  whether  inst  n  J^'^^'V? P"^^^'^°*  ^^'^S  to 
a  non-intelligent  mode  of  oS  th     '  ^'^  '"^  intelligent  or 

their  fuU  formation  come  into°contnnf^  >^^^  f  n-"^  '^^  ^^^^^ 
point;  so  that  theTo  s^'s'^f^'^^^ 
embodiment  of  aU  the  foreioiL  f  T  ^^°'^"^  (^^'^S  the 
illustrate  at  once  the  3'  "/I^^T?  ^P^"  *^e  subject) 
opinion  which  has  been  so  n^^on '^'  ^f''^y'^  the  common 
he  sar  of  instinct  and  rein  Stw'^'^.i^^  ^^P^'  ^^^^^ 
separate,  yet  for  ever  LZT  ^   '^  ^^'"^'  "^^^  ^ver 

precLtg'cCte'rsTl^^^^^^^^^^^  ^  ^"^-^  — y  of  aU  the 

Instfn^rilLrfded^^^  ^^-e  I  use  the  word 

tion  of  instinct  as  exSd  tV  ^"^^^^^^^ 
animals  without  indivX«    1  ^  ^^'^  ^°""«  animals,  or  by 
to  which  their  ins  LXt^^^^^^^^^  ^^^  circumstance! 

a  few  complementary  mLtrSs  of  H  '^'''^'  .^^^^  ^  g^^« 
stmct,  and  pointed  out  tW  .    t  °    the  imperfection  of  in- 

either  from  Lhange-n  the  eoSr^  "^'S^'  ^"«e. 

which  the  ancestral  in.h-nnf  ''°''^'  ^^^^^  ^^  the  environment  to 

the  instinctTno  ye"^^^^^^^^^^  ^\^^om  the  fact  that 

mperfection  of  instinct  St  ^if"?'^'    -^  ^^''  '^^^'^^  that 


K( 


EXAMINATION  OF  THE  THEORIES  OP  OTHER  WRITERS.   267 

interrupted  for  a  time  anrarr  rented      TZT'"''''  '' 
case  of  such  derangement  wh^vJlh        -i   /  ^^^'^^  gave  one 

interruption    and  whir^\pT.f        ^'^  ^^^  ^^^^  "^^  such 
regardeLs^caseof  i^tnt  '  ""'^  "'"'  ^''^'''^   ^' 

with'lr^e-^eVin^^a^^^^^^^^  ^^  -t 

young  chickens  beirffihCVr^"^'^  ''  «^^«. 

instead  of  runninTaw^    r^m'^ltTs't'l^^^^^ 

also  see  instincts  in  course  of  ZTT'        1     ""■     ^  ^  "^^>^ 

children  learning  to  bahnpp  ft  J  ^^^P^^^nf,  among  young 

Moreover  all  causes  of  tl^p.^      .        '  ^"^  "^^'^^^  ^'^  'P^^^^'  &c! 

•stinct,  whether TZ  Mv  dudt'inThr^"'^"^"^  °^  ^-" 

cases  oi   the    original    imw!;^        ?^  race,  are  so  many 

brought  us  diiecarLn5     '''^-  ^^  '^'^^°'^<=-     ^"^   this 

instiScts.  ^  ""^"^  ^^'  'l^^^^^^^  a«  to  the  origin  of 

ma/  brw,t?rh:^^i7eihef.^'^  °"°^"  ^^  -^-^« 

That  is  to  say  I  believe  tW  ,"!  ,  ^"-.^'^  °'  secondary, 
instincts  may  arise  e'lherhv.L^"'^  ^  '''''  ^°  '^"^  ^'^^^ 
poseless  habTtsvWd  lance  TZ  ^'T  ^"^"«  °^^  P^^- 
these  habits  intrSstincts  withm^^^'f  5?  ''  '"  converting 
concerned  in  the  pioces^  nAt  P  ^^'''  ^  ^'"'''  ^^^""  ^^^^ 
becoming,  by  -^eS 'a^m^a^^^rri^^^^^^^^^ 

sCnZyrtStsVC:  rr^^^^   aU  as^  Splef  of 
perfect."^  Cd  tL^'^U^^' ^  ^^^^^  1 "  Practice  making 

and,  haria-^lZed  from  tfpS-''''"''''™  ¥'""<'  »'»■»»««. 

and  AeykopeTi7CnZJ^{]itJlt^'Z  "T'T'  '"'>''"« 
the  previous  and  ana  o  -ous  Zl  \Zr  't"'""-  ^  » 
t.on.  were  substantiated  by  showin-  fct™tht^?T™'; 
manner  e.  displayed  more  o/les.  brever^l.tl  e^^  L"/ 


I  ;;;.:.; 


268 


MENTAL  EmUTION  IN  ANIMALS 


;i 


I! 


craciee    formin  "  »L      mcUvKlual  disposition  and  idiosvn- 

automati  aTrfiele  "SfortSrr'!'?''  *"••  ''^«^''  *■>-' 
amply  proved  by  ca  e  in  wh  ch?2 L  K"  "'^  i"*"™'! '^'  ^"^ 
triclcs  of  manner  di,nI„;t,T^,?  ^'  '*?"  obsofved  of  the 

nou-intelli^ent.  or  purSs7haSr.hi  n''*  '"'^5  inherited, 
of  certainty;  seeing  tlr  «?«.!/  I  "'*'  y^""^' ''  ^  "^^"er 
habits  ma/do  so  a^nd  Lt  even  '^^fT'^'^y.  «!">^n.  useful 
plastic ;  much  moie  tl.Pn  1  .  !?"^  ^?™^^^  "^^^^^^^3  are 
habit  be  variable  tU  V  ;w'^  ^^'^'l  fortuitous  sports  of 
directions  teva^^^^^^^^  ^^^  ^^^)^  ^'-^  Profitable 

natural  selectionTs  uoTss  a  matt.f  nf  ^  T^t  ""^  ^^^^  ^^ 
be  questioned  by  any  one  wh^tSl^  certainty,  and  m  .11  not 
as  a  principle  concorno^fnTi  ^''^J^'  '^  ^''^'^"^al  selection 
Thus  only^can  '^;'*^^^^^^^^  ^  ^^g'-^^""'  structures, 

(such  as  the  caddis- wolVo.H^^^^^^^^^       ""'""^  ^^^  ^"^^^Is 
(such  as  that  ofinXt^^nf  Tor '"''^ 
instincts,  it  was  first  sWnH^^  ''^''^  ^''  secondary 

frequently  perform  d  become  1^^^^^^^ 

and  next  that  thTy  areTh^ritef  tm  hI:  '^  '^''  ^"^^^"^^^^^^^ 
habits  in  the  race.  The  former  ftf  if '^ -v''^  automatic 
the  latter  was  proved  bvsurb  .«=  """Ti^'^'  ^"  "^^^^  o^^; 
■  handwriting  family  anS,X?  f  '"'  ^'  *^°'^  ^^  hereditary 
characteristics  0  Ve^^^^^^^^^^  in'Jf'"'''^^^'^J  f  ^^^'^^t^'  ^^^e 
sense  of  modesty  ^In  anS.  fh.  '"'  ^°°^  ^''^^'''S,  and 
an  hereditary  tendency  lo^ht '  ^•  '^ '  ^''T^^'  ''  '^'^  ^^ 

ponies  fromVwayVot  ha^^g  ^^m^olt^s'"'' dTh"  ^-^^^  ^ 
dog  present  ng  an   inherited  »,?n„^%     .  '  ^   '^■.^°8S«is'3 

animals    showing   a^tSet"    Cr\  %he\f  ^^^^^^^  1'^ 
enemies,  such  fear  beinrr  in=f  oo  I        i  ^®^^  particular 

animals'Cnotably  in  th!  rabbit  Zf  T^^l"  '^''^'^"''ated 
not  likely  to  have  had  anv  ™rf  .™d  duck,  where  selection  is 

ness);  an^imalsXinfoZeCclffdfl'^™'"'-^^"" 
man  for  several  geSerS;ions  aftefhl  /  r'"?"  "^         °^ 
them,  then  acqui^g  inZetfv  "di^ead  o?h?m™and'™"^ 
learnms  what   constitutes   safe    dist^nce^S'  Se-arr. 


ifi 


^fl^CoLlJ^ --^-^-"^  ^^-i^cts  Of  blend- 
fat  inScTs  L^"  S  tri'u^l^-  -^-ted  examples 

aps,ng  intelligence  alone    the  rW     '"^"'""^  "lone,  or  by 
that  instincts  in  aenemlnro     ?"*'"«'''<>«  went  on  to  show 
or  oti      ,,  ,,^3^  tCrodeTofl.i"4r^^^^^^  confinei^t: 
that  these   principles   when  worK' ■' ^'^  *^^^  contrary 
^eate)     .fluence  in  evol^l'lZtZV'^,. '''^'''''^'^  ^a/e 
can  have    .vhen   working  siSX      p  '  '^^"^  f  ^^^^^  ^^  them 

hereditary  proclivities  or  hatotupHn''  "M^"  «"«  hand, 
though  never  intelliapn/  T        ^^  °"^  ^^^^ch,  bein^^  usefnl 

selection,  may  coSf fu '  ^f'  'f ^  """>^  ^^^^  by \ata  a 
^ent  or  be  '"putTo  Jt  er^terbv ?n.  f-  ^^^^^  i-Prove' 
versely,  adjustments  originallv  dl  J^r^'"j«'"''' '  ^ndf  con- 
come  to  be  greatly  impiCd  or  «».  ?  ^?T^  intelligence  may 
selection  For,  taking  the  Sr.''^1'^^  ««««'  by  natural 
seen,  intelligent  actions  may  b™?H  T' ^^'  ^«  ^«  h'-^ve 
as  secondary  instincts,  and  ^if  S!^l\^°f, ^^^^^^^  automatic 

their  variations  iixed  in  ben^ciaTS  ^^^"  ^^ry  and  h«ve 
how  much  more  scope  may  bp  1      ?  ^-^  "^^"^^^  selection 
this  further  develop^LTof  an  instL'f'  "/'f  ^^  selection  in 
this  instinct  are  not  wholly  fortu2t>      ^^'  ™^tions  of 
adaptations  of  ancestral  experLnrp  .    ^  """'"  ^'  intelligent 
^ents  of  individual  experience     rl'?'  ^'''^^^^^  ^«q^">«- 
mustm  suchacasebewSrf'nf?    '^-l'  ""^^"^^^  selection 
than  It  does  when  working  S  t  th?T^  ^?'^^  ^^^^"^age 
instincts,  where  it  is  qimt^Kn J      ,       ■     formation  of  primnrv 
instead  of  with  va4   K^^^^^^  vai?SZ 

gence.  are  from  the  first  a^Xl     itT'^r'^  ^7  inteUi- 
principle  of  lapsing  intemSp  n,'    A^  """^  ^^^«  ^^early,  the 
,   greater  advantL  when  thu??n"'*^''^^^^^ng  at  a  much 
tion,   than  it  i?  ZheVwZTJ^^^^^^^^ 

always  tend  to  favour  tL  be  t If  ±  Tir"  ^^"'  '"'"  ^"^^ 
and  by  concentrating  the  power  of  hpf  f !'«'"^  adjustments, 
tend^ ..  more  speedily  to^^^Sef  S^roL^.t^^^^^^^^ 

-^f^}^7^;^:;SV^^^  Origin, 

natural    selection  or   lapsing  ^^Sl^^^tX:^'^^^ 


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Sciaices 
Corporation 


23  WEST  MAIN  STREET 

WEBSTER,  N.Y.  14580 

(716)  872-4503 


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270 


MENTAL  EVOLUTION  IN  ANIMALS. 


fuJ 


historic  priority,  even  if  from  the  first  these  two  principles 
have  not  been  in  combination;  the  important  fact  to  be 
shown  is  that  even  a  fully  formed  instinct  may  prove  itself, 
under  the  influence  of  intelligence,  variable  or  plastic.  I 
therefore  demonstrated  the  plasticity  of  many  existing 
instincts,  dwelling  especially  upon  the  cell-making  instinct 
of  bees,  and  the  incubating  and  maternal  instinct  of  warm- 
blooded animals — choosing  these  instincts  for  special  con- 
sideration because  they  must  be  of  so  ancient  an  origin,  and 
are  so  strongly  inherited. 

Intelligence  may  operate  in  the  modification  of  instinct, 
either  by  perceiving  the  need  of  a  change  in  the  dictates  of 
heredity,  by  intelligent  imitation  of  the  habits  of  other 
animals,  or  by  parents  intentionally  teaching  their  young. 
Copious  facts  on  all  these  points  were  therefore  given.  But 
the  best  evidence  of  the  extreme  modification  which  instincts 
may  be  made  to  undergo  by  the  combined  effects  of  intelli- 
gence and  selection,  is  that  which  is  afforded  by  the  facts  of 
Domestication.  These  facts  were  therefore  detailed  at  length, 
and  they  showed  that  domestication  has  not  merely  a  nega- 
tive influence  in  eradicating  natural  instincts  (witness  the 
loss  of  wildness  in  dogs,  cats,  horses,  and  cattle ;  dogs  not 
attacking  sheep,  pigs,  or  poultry ;  the  latter  having  lost  their 
instinctive  fear  of  dogs,  so  differing  from  pheasants;  the 
incubating  instinct  being  lost  in  the  Spanish  hen,  and  the 
maternal  instinct  in  cows  and  sheep  where  the  young  have 
for  generations  been  habitually  removed  from  their  mothers 
at  birth ;  Polynesian  dogs  having  lost  their  natural  intelli- 
gence, together  with  their  natural  taste  for  flesh) ;  but  also  a 
positive  influence  in  developing  new  instincts.  In  the  case 
of  the  Dog  these  new  or  "  artificial "  instincts  were  shown  to 
be  strikingly  exhibited  in  the  sheep-dog,  pointer,  and  re- 
triever ;  but  perhaps  still  more  remarkably  in  the  instinctive 
love  of  man  shown  by  nearly  all  the  breeds ;  faithfulness  to 
and  sense  of  dependence  upon  man  ;  inborn  idea  of  protect- 
ing his  master's  property  and  of  himself  as  constituting  a 
part  of  that  property ;  barking  being  an  acquired  instinct, 
and  probably  arising  from  this  idea  of  protecting  his  master's 
property.  Indeed  so  fundamental  has  been  this  psychological 
transformation  in  the  dog,  that  the  artificial  instincts  have 
frequently  become  stronger  than  even  the  strongest  of  the 
natural  instincts,  viz.,  the  maternal — as  is  proved  by  cases  in 


iP^HIi 


EXAMINATION  OP  THE  THEORIES  OP  OTHER  WRITERS.      271 

which  the  latter  has  given  way  when  in  conflict  with  the 
former.  Lastly,  I  devoted  a  chapter  to  the  consideration  of 
local  and  specific  variations  of  instinct,  showing  how  these 
constituted  a  kind  of  paleeontological  evidence  of  the  trans- 
mutation of  instinct. 

Such  then  is  the  dj  posteriori  proof  of  the  two  ways  which, 
either  singly  or  in  combination,  must  be  regarded  as  those  by 
which  all  properly  so-called  instincts  have  been  developed. 
A  diagram  was  given  to  show  graphically  how  the  sundry 
principles  concerned  are  related  and  inter-related  with  one 
another.  Here  it  was  shown  that  when  an  instinct,  whether 
of  single  or  blended  origin,  was  perfected,  it  might  vary  or 
ramify  into  modified  forms,  and  even  blend,  or,  as  it  were, 
inarch  with  other  instincts  to  produce  a  new  growth.  It  is 
difficult,  or  rather  imJ)ossible,  to  trace  the  history  of  actual 
instincts  in  this  respect,  from  the  fact  that  instincts  are  not 
fossilized,  and  therefore  leave  no  record  of  their  transi- 
tional states.  But  from  all  the  evidence  together— and 
especially  from  what  we  may  almost  denominate  the  historical 
evidence  supplied  by  the  facts  of  domestication— there  can  be 
no  reasonable  doubt  that  instincts  may  not  only  have  a  double 
root — one  in  the  principle  of  selection,  and  the  other  in  that 
of  lapsing  intelligence— but  also  a  more  or  less  branching 
stem,  which  (or  the  branches  of  which)  may  in  some  cases 
become  grafted  with  the  stem  or  branches  of  other  instincts. 

In  estimating  the  comparative  importance  of  the  two 
great  factors  in  the  formation  of  instinct,  we  had  occasion  to 
differ  on  the  one  hand  from  Mr.  Spencer,  who  attributes  the 
origin  of  all  instincts  to  reflex  action  with  little  or  no  aid 
from  natural  selection,  and  on  the  other  hand  with  Mr.  Lewes, 
who  goes  to  the  opposite  extreme  of  regarding  all  instincts 
as  cases  of  lapsed  intelligence.  It  was  shown,  however,  that 
Mr.  Spencer's  view  might  be  held  to  explain  the  rise  of 
doubtfully  instinctive  actions  displayed  by  very  low  animals, 
and  that  it  is  of  much  importance  as  an  explanation  of  the 
origin  of  Consciousness.  The  view,  however,  which  I  adopt 
to  explain  the  origin  of  instincts  is  substantially  the  same  as 
that  which  has  been  propounded  by  Mr.  Darwin,  and  which, 
while  recognizing  both  the  factors  which  I  have  now  so 
repeatedly  named — i.e.,  natural  selection  and  lapsing  intelli- 
gence—whether singly  or  in  combination,  attributes  most 
importance  to  the  former,  especially  if  it  be  remembered  that 


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272 


MENTAL  EVOLUTION  IN  ANIMALS. 


in  Its  work  of  organizing  instincts,  intelligent  adjustment  is 
always  nnder  the  direction  and  control  of  naturll  selection 
80  that  Its  chief  function  in  the  formative  process  is  probablv 
that  of  supplying  to  natural  selection  variations  of  ancestral 
instincts  which  are  not  merely  fortuitous,  but  intentionally 
adapted  to  the  conditions  of  the  environment 


i 
1 1 


SIMILAB  INSTINCTS  IN  UNALLIED  ANIMALS.  273 


CHAPTER  XVIII. 

Instinct  (cmtinued). 

^'''^rn?v/T ''''''  Difficulty  with  Eegard  to  the  Fore- 
iNsmcTr''''''  °^  ™^  ^^'^'^  ^"^  Development  of 


We  must  not  take  leave  of  Instinct  without  looking  into  aU 
the  known  cases  of  its  exhibition  which  admit  of  being 
reasonably  cited  against  the  views  here  expressed  on  the  risf 
and  development  of  instincts  generally.  I  shall  therefore 
consider  senatim  all  such  cases  whicL.  L  have  met  with  in  the 
writings  ol  others,  or  which  occur  to  me  as  admitting  of  being 
possibly  cited  in  this  connection.  ^  ^ 

Similar  Listinds  in  Unallied  Animals. 

meef  wShThP  tr'^''  ^^  \^^  Appendix,  "  We  occasionall 
meet  with  the  same  peculiarinstinct  in  animals  widelv 
remote  m  the  scale  of  nature,  and  which  conseqSy  Tannot 

Tre'diStv  of'.  P""'"1'^  '^^^  communitVof  de  cent ' 
Ihe  difficulty,  of  course,  is  to  account  for  the  parallelism  and 
the  instances  given  by  Mr.  Darwin  are  those  ot'the  Shrus 
having  the  same  mstinct  of  parasitism  as  the  Cuckoo  the 
Termites  having  much  the  same  instincts  as  the  AnLand  a 

o7ZC"  ?Jtin';P'"'"^  '"^^  \^^^^«"  ^^-  satfinstinc? 
tbp  l£?    ^  a  pitfall  for  prey.     He  shows  satisfactorily  that 

cukv  w'''^''''t^  ''  ^^'  °^^  ^^^^  ^^^^  offers  any  rea/iffi. 
culty ;  but  even  here  it  seems  to  me,  the  difficulty  is  not  one 
of  any  magnitude.  For  the  instinct  in  question  is  not  one 
fn^f  ^^°\Ple^i<^ys«r  of  such  remote  probabiSty  as  to  i?3 
formation  where  a  larva  habitually  lives  in  sand  that  4« 
may  not  readUy  believe  a  similarity  of  envTrorment  shouW 
have  determined  its  development  independentlyTtwo  Unes 


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274 


MENTAL  EVOLUTION  IN  ANIMALS. 


m}, 


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'     ii 


of  descent— just  as  for  the  same  reason  wings,  for  example, 
have  beeu  developed  independently  in  at  least  four  lines  of 
descent. 

JDissimilar  Instincts  in  Allied  Animals. 

Mr.  Darwin  in  the  Appendix  also  alludes  to  this  subject, 
and  the  few  remarks  which  he  makes  upon  it  seem  to   me 
fully  to  dispose  of  the  difficulty— which,  indeed,  with  his 
characteristic  candour,  I  cannot  but  think  that  he  unduly 
magnifies.     As  I  have  observed  in  my  chapter  on  Local  and 
Specific  Variations  of  Instinct,  the  theory  of  the  formation  of 
instincts  by  natural  selection  really  leads  us  to  anticipate 
the  not  infrequent  occurrence  of  what  we  may  term  isolated 
instincts ;  for  only  if  we  were  to  suppose  that  all  considerable 
variations  of  instinct  (local  or  otherwise)  are  permanent, 
could  we  anticipate— in  the  absence  of  any  palaeontology  of 
instinct— a  graduated  series  of  instincts  in  all  cases,  with  the 
consequent  absence  of  isolated  instincts  in  every  case.     But 
to  suppose  this  would  be  to  run  counter  to  the  first  principles 
of  our  theory.     Of  course  if  specific  instincts  were  of  very 
general  occurrence,  it  might  reasonably  be  objected  that  this 
theory  would  require  to  suppose   too  great  a  slaughter  of 
intermediate   species  to  be   accepted  as   credible;    but  as 
matters  actually  stand  I  have  felt  that  the  occasional  appear- 
ance of  isolated  instincts  in  about  the  proportion  of  cases 
that  the  thsory  would  lead  us  to  anticipate,  really  constitutes 
a  corroboration  of,  rather  than  an  objection  to,  the  theory. 

Trivial  and  Useless  Instincts. 

Mr.  Darwin  in  the  Appendix  also  refers  to  trivial  and 
useless  instincts,  and  says:— "I  have  not  rarely  felt  that 
small  and  trifling  instincts  were  a  greater  difficulty  on  our 
theory,  than  those  which  have  so  justly  excited  the  wonder 
of  mankind  ;  for  an  instinct,  if  really  of  no  considerable 
importance  in  the  struggle  for  life,  could  not  be  modified 
or  formed  through  natural  selection." 

This  is  no  doubt  an  important  point,  and  must  be  care- 
fully considered.  First  of  all  it  ought  to  be  observed  that  if 
any  such  difficulty  can  be  shown  to  stand  against  the  theory 
of  the  formation  of  instinct  by  natural  causes,  much  mora 
must  the  difficulty  stand  against  the  older  theory  of  the 


m. 


TRIVIAL  AND  USELESS  INSTINCTS.  275 

implanting  of  instincts  by  a  supernatural  cause.  Next  we 
must  be  perfectly  sure,  in  any  given  case,  that  the  instinct 
which  appears  to  be  trivial  or  useless  is  ieally  such  ThL 
point  IS  mentioned  by  Mr.  Darwin,  and  he  cities  some  very 
good  cases  to  show  how  the  important  utility,  or  eveTabsZ 
lute  necessity,  of  an  instinct  may  readUy  escape  observatb^ 
But  even  after  due  allowance  is  Lde  on  this  score  some  ew 
instincts  certainly  do  remain  which  it  seems  impossTble  t^ 

I  believe  they  admit  of  being  satisfactorily  explained  bv 
two  considerations.  The  first  of  these  is  that  our  theory 
does  not  suppose  natural  selection  to  be  the  only  influence  at 
work  in  the  formation  of  instincts.  We  have  reputedly 
insisted  hat  the  lapsing  of  intelligence  is  another  iSfluen^ 
of  scarcely  less  importance;  and  we  have  also  seen  abundant 
evidence  to  show  that  non-adaptive  habits  occur  in  indi. 
V  duals  and  may  be  inherited  in  the  race.  Therefore  ^f  from 
p  ay  affection  curiosity,  or  even  mere  caprice,  the  ntelLe^^^^ 
of  the  animal  should  lead  the  animal  to  perform  any  useless 
kind  of  action  habitually  (as,  for  instance,  in  the  S  of  tl  e 
ratels  tumbling  head-over-heels),*  and  if  this  habi   were  to 

«hn,'l  1\  ''''^f '^  ?  ^^'  '^''^^''-y  constituted  progeTy  we 
should  have  a  trivial  or  useless  instinct.    The  only  condition 

heV"t"f''Y'''''T^^l''i''^'  '^  be  sati^sfied  would 
be  that  the  trivial  or  useless  habit  should  not  be  actual  v 
detrimental  to  the  species  exhibiting  it.  so  Siat  its 'S 
iiUo  an  instinct  should  not  be  ^revLed  bynaturd^seree- 

The  other  consideration  to  which  I  have  allnrlo^   a. 
mitigating  or  dispelling  the  difficulty  t  question  iftMs     S 
the  analogous  case  of  structures,  as  is  well  known,  we  meet 
with  innumerable  cases  of  useless  organs;  but  heres^f-ir 
f^om  the  fact  being  deemed  a  difficulty  in  the  wayVf  the 
theory  of  evolution  by  natural  selection,  it  is  justifdeemed 
one  of  Its  strongest  supports;   and  the  reason  is  tharin 
all  such  cases  we  have  evidence  of  the  useless  and  perham 
nidimentary  organs  being  of  use  in  other  and  aUied  aSafs 
Now  I  see  no  reason  to  doubt  that  the  same  may  be  true  of 
instincts    and  therefore  that  what  we   now  find  to  be  ap- 
parently trivial  and  certainly  useless  exhibitions  of  hereditaiy 

•  See  p.  189. 


•1 


!  '  I 


■I 


,  it 


I'  -l 


iii  ■' 


m 


m 

m 


II 


I?i 


276 


WJ* 


VS  ' 


MENTAL  EVOLUTION  IN  ANIMALS. 


of  ofTJ'n^lV^''  earlier  period  in  the  history  of  the  species 
or  of  Its  al  les,  have  been  of  real  utility.  We  may  for 
example,  readi  y  imagine  that  the  instinct  displayed  by  many 

^s'tJllv^V"^"""^'  °^  ^"""S  '''^  ''  wounded  companions^ 
Lr^f^  ■  T  i"  ^°""t"««  «^here  the  presence  of  weak 
members  in  a  herd  is  a  source  of  danger  to  the  herd  from  the 
prevalence  of  wild  beasts;  and  Mr.  Darwin  in  the  ApZidk 
gives  evidence  that  such  is  actually  the  case.  Or,  to  takH 
more  fanciful  il  ustrat  on,  we  may  suppose  the  Megapodid^ 
mentioned  m  the  Appendix,  which  incubate  their^eS^s  by 
placing  them  m  a  large  heap  of  fermenting  ve^'Btable  mtter 
which  they  collect  for  this  purpose,  we?e  to^find   fSm  a 

t^^fm  '^Z^-'^^f  ^'  °^  *^"  Australian  climat^.  that  tt 
was  difficult  to  collect  a  sufficient  quantity  of  vecretable 
mavter  or  that  it  would  not  ferment  sufficiently  for  the  pur! 
poseofmcubation  The  birds  might  then  gradually  revert 
to  the  usual  mode  of  incubation,  but  might  still  retain  a 

ZS  T?'''^'!;?^^/?  ™^^'  *"°^"^i  ^^  ^^g^table  matter  as 
S;i  I  ^\  ^^  labour  expended  in  making  such  tumuli 
would  be  obviously  useless,  and  there  bein|  no  analogy 
among  the  mcubating  habits  of  other  birds  to  give  us  a  clue 
as  to  the  origin  of  such  an  instinct,  we  should  be  quite  at  a 
loss  to  account  for  it.  «^  "u  «, 


w.  m 


Instincts  apparently  Detnmental  to  the  Species  which 

exhibit  them. 

It  constitutes  no  difficulty  or  objection  to  our  general 
theoiy  of  instinct-formation  to  point'  to  cases  in  whlchTn- 

mS.r?>,'^'^T^^v^'.'""^^"*"^  *°  '^'  individuals  whch 
manifest  them ;  for  it  is  of  the   essence  of  the  theory  of 

natural  selection  to  suppose  that  the  interests  of  the  [ndi- 

vidual  are,  in  the  process  of  selection,  subordinated  to  those 

of  the  species.     It  is,  for  example,  manifestly  to  the  dS 

rnHplr-'^'^'^^^-r^-^^.^^P^*^^^^^^^  '''  kind, inasmuch  asS, 
own  death  is  speedily  mduced  by  the  act;  but  seeing  that  the 
act  IS  essen  lal  to  the  continuance  of  the  species,  we  perce  ve 
whT.rlT^  selection  must  here  have  developed  an  Snc? 
which  virtuaUy  amounts  to  that  of  suicide.  And  the  same 
remark  applies  to  all  siniilar  cases,  such  as  that  alluded  to  in 
Animal  Intelligence"  of  soldier  ants  and  termites  sacrificino 
tliemselves  for  the  benefit  of  the  community-i.e.,  the  species 


i : 


M 


INSTINCTS  APPARENTLY  DETRIMENTAL  TO  THE  SPECIES.      277 
But  of  course  the  case  is  entirely  alterpH  wliom  -«,« 

another,  It  would  annihilate  my  theory  "  TnH  it  t  S- 

s:is:  ^""^  '^""■^  -""  «%p.;loih':  °ctro? 
Of  a^  w;is4f rsrs:Th:tr  tt:  r::^ 

one  case,  either  of  an  instinct  which  ™detrim!r?n?  f„  ,7 

Tlu  beneflfof  '\r  "'  ™^.  ^'"'"^  ■>-  -^'1'°  fee" 
10  tne  benefit  ot  other  species.    For,  on  the  ohp  hnnri    if 

here  is  any  one  such  case  of  an  indispitable  Ld  ^^^^^^ 
clearly  have  to  modify  our  whole  theory  in  orSr  to  meet  it 
while,  on  the  other  hand,  if  there  is  no  such  case  thXt  of 
obvious  SeTtlf '  ""''^'^^^  i'  ^"^^^1  instinctrbing  of 

of  Txclus  ve  nS  tn^nJJ.''  ""^"'^  "^""^^^^^  ^^«°^'  ^°d  never 
VI   exclusive   use  to  other  species,   must  be  takpn  aa  fi^^ 

strongest  possible  evidence  of  the  theory  that  ascribes  aU 
mstincts  to  the  causes  which  we  have  assigned 
^oo/  T^  ^'  "^^^  '^^  ^*  °^<^^  *^^a<^  there  is  only  one  apmrenfc 
wl'^^r 'f  ^^!?"*^  ^'^  °^^  ^P^'^ies  having  exclusive  refer' nee 
bei^eficLuf  thi '"°''"'  ^^^'^"^^^  ^^-^  -^  casrof  St: 
to7tL  spe^^^^^^^  "%7^  frn?^^  '^^^  '^^^^^  ^1«^  beneficial 
cLcerned     Th.  f  <^he  latter  cases  we  are  not,  of  course, 

concerned     The  former  is  the  case  of  aphides  vieldina  im 

m^ZT^'w  '""'"'r^  ""''  already  b'een  consS  Ij 
Mr.Darwm.  His  explanation  is  that,  "as  the  excretion  i^ 
extremely  viscid,  it  is  no  doubt  a  convenience  to  the  apSs 

^naLXXZl^fef'  '''-"'  '^^"  '^^  ''''  ''  ^^«  -"!«  oi  the  rattl.. 


t, '  '■ 


''ii'  m;i 


iiii 


i!  n 


'  H 


278 


MENTAL  EVOLUTION  IN  ANIMALS. 


to  have  it  removed;  therefore  probably  they  do  not  excrete 
solely  for  the  good  of  the  ants."^ 

Coining  now  to  the  other  branch  of  the  subject,  after  due 

ll^Z  ""  \^^l  ^^^y}^^^  ot'  two  or  three  instincts  which 
could  possibly  be  cited  as  presenting  the  appearance  of  bein- 
detrimental  to  the  species  which  manifest  them.  I  shall 
therefore  consider  these  cases  separately 

«,,T.Lf'*'ifl''"^/''T?^-~~^^^  ^^""^^  ^f'the  evidence  on  this 
subject  will  be  found  m  my  other  work.f  It  will  there  be 
seen  that  two  or  three  independent  witnesses-including  a 
friend  of  Dr.  Allen  Thomson  ou  whose  accuracy  he  says  he 

tw'S  '"'  *''^""""^  *°  ^^"^  ^^^^^  °f  the  popular  saying 
that  when  a  scorpion  is  surrounded  by  fire,  or  otherwise 
exposed  to  undue  heat  it  will  commit'suicide  by  stingin' 
Itself  to  death.  It  will  be  seen,  however,  by  referring  to  h? 
correspondence  in  question,  that  the  alleged  facts  are  disputed 
by  other  observers,  and  also,  as  I  have  already  indicated  that 
they  were  not  observed  by  Dr.  Thomson  himself. 

_  The  effect  of  republishing  this  correspondence  and  of 
pointing  out  the  desirability  of  obtaining  further  evidence 
upon  he  matter  has  been  to  induce  tv?o  verrcompeten? 
naturahsts  to  make  some  observations  upon  the  subject.  One 
of  these  naturahsts  is  Professor  Lankester,  who  published  his 
observations  m  the  "  Journal  of  the  Linnean  Society  "  (1882) 
and  the  other  is  Professor  Lloyd  Morgan,  who  published  hi<,' 

agree  that  the  scorpions  never  commit  suicide,  and  as  Mr 
Morgan  exposed  f  ht  animals  to  a  variety  of  dreadful  tortures 
with  a  umtormly  negative  result,  I  think  the  question  may 

.  .  ^  .f  "'"'''^^.'■^^  ^  ^^^^^'^-  Moreover  Mr.  G.  Bidie,  who 
started  the  previous  correspondence  in  "Nature,"  has  recently 
addressed  another  letter  to  that  Journal^  in  which  he  makes 
the  not  improbaDle  suggestion  that,  as  in  his  experiments  he 
applied  heat  by  condensing  the  rays  of  the  sun  with  a  lens 
upon  a  small  point  of  the  scorpion's  back,  the  animal  in 
stinging  Itself  "  may  have  merely  been  trying  to  get  rid  of  an 
imaginary  enemy."  /    o      o«i'  xau  oi  an 

2.  ^^c^/s/i/^n^^-Aroj/^A/^fowc— The  determination  shown 
by  many  kimis  of  insects  to  fly  towards  and  through  a  flame 
18  unquestionably  due  to  instinct,  and  as  such  mi|ht  be  ad- 

•  Onjr,,  of  Species,  p.  208.  +  Animal  Intelligence,  pp.  222-5. 

t  July  12,  JS83.  "       '  ff 


INSTINCTS  APPARENTLY  DETRIMENTAL  TO  THE  SPECIES.   279 

duced  as  evidence  of  an  instinct  detrimental  alike  to  the 
individual  and  to  the  species.     But  before  this  conclusion 
could  be  reached  several  possibilities  reauire  to  be  attended 
ta     In  the  first  place,  flame  in  Nature  is  an  exceedingly  rare 
phenomenon,  so  that  we  comld  scarcely   expect  that  any 
instinct  should  have  been  developed  for  the  express  purpose 
of  Its  avoidance.    Therefore,  if  the  general  economy  of  ni<dit. 
flying  insects  is  such  that  it  is  of  advantage  to  approach  "and 
examine  shining  objects,  there  would  be  notliing  anomalous 
m  their  failing    to  distinguish  between    flame  and  other 
shining  objects— such  as  white  flowers  or,  in  the  case  of 
moths,  pale  coloured  members  of  the  opposite  sex.     But  as 
the  instinct  of  flying  into  flame  is  of  such  general  occurrence 
among  many  species  of  insects,  I  think  we  certainly  cannot 
attribute  all  the  cases  of  it  to  a  mistaking  of  flame  for  soma 
other  shining  object;  to  meet  all  the  cases  some  still  more 
general  explanation  is  required,  and  this,  I  think,  is  aff-oided 
by    considering   other    and   analogous    cases.     Thus  many 
species  of  birds  display  an  exactly  similar  propensity,  as  is 
proved  by  the  experience  of  lighthouse  keepers;  and,  accord- 
ing to  Professor  A.  Newton,  some  species  of  birds  are  more 
readily  attracted  by  light  than  others.*     Here  there  can  be 
no  question  about  a  possible  mistaking  of  flame  for  white 
flowers..  &c,  and  therefore  the  habit  must  be  set  down  to 
mere   curiosit3%  or  desire  to  examine  a  new  and  striking 
object ;  and  that  the  same  explanation  may  be  given  in  the 
case  of  insects  seems  not  improbable,  seeing  that  it  must 
certainly  be  resorted  to  in  the  case  offish,  which,  as  I  pointed 
outm  "Animal  Intelligence,"  are  likewise  attracted  by  the 
light  of  lanterns,  &c. ;  and  the  psychology  of  a  fish  is  not 
much,  if  at  all,  in  advance  of  that  of  many  insects. 

Thus,  in  any  case,  it  seems  certain  that  we  have  no  reason 
to  regard  the  propensity  in  question  as  an  expression  of  any 
instinct  specially  formed  with  reference  to  flame,  and  this  is 
really  the  only  point  with  which  we  are  directly  concerned. 
But,  as  the  subject  is  in  itself  an  interesting  one,  I  shall  here 
add  a  few  remarks  with  reference  to  other  aspects  of  it 

Among  Mr.   Darwin's  MSS  I  find  the  following '  note 
which,  however,  is  not  in  his  hand-writing. 

"  Query.  Why  do  moths  and  certain  gmits  fly  into  candles, 
and  why  are  they  not  all  on  their  way  to  the  moon— at  least 
•  Yarrell's  Brit.  Birds,  4th  ed.,  II,  235 


■lill 


1 

if 

11 

■ 

1 ' 

•  * 

■  1 

1  .; 

280 


MENTAL  EVOLUTION  IN  ANIMALS. 


Ki.  ' 


Let  a  cloud^sa  over  and  S'v    '  °"  "  ■""""■'ifc*'  ni«l.t 
camlle."  owr,  and  they  are  again  attracted  to  the 

quo^rf-fr'trsat^'nhe'o  °''""?}'°"  '^  "^  •  ^•"  ^ 

:="to  a^  ^srv-rf  £<3'-F- 

would  approach  it.  '  ^'"'^  "'^^'^'^  '^"^  P^^ats 

writes  :1^'''''"  ^^"^  ^"^'  P'  ^^C)'  ^r.  J.  S.  Gardener 

"  Whilst  watching  the  great  horse-shoe  falls  of  thfi  «?Hni 
fandafljot  near  Sjosavan  in  Iceland  I  «aw  mnfi?    5'f       '^''l" 
%  deliberately  into  the  fallin'  waL  "'d  Zn/^''  S"""^^ 

much  as  a  gleaming,  waterfall  i7r,nf  1       2  •    P?^^^'  ^"^«- 
object  in  Nature  eitheT to  fni   •  ^P^^fficiently  common 

^«. change  of  envirt^^nTtK  /^/rCtytLTX: 
such  a  change  haa  taken  place,  time  mustT  aUowed  t? 
the  compensating  modification  of  the  instinct-even Tnppoaf 


INSTINCTS  APPARENTLY  DETRIMENTAL  TO  THE  SPECIES.  281 

ing  that  any  such  modificntion  is  ur"cntlv  rpnnim,!     xr 
can  scarcely  be  held  probable  on  tCe  VriSs  ZZ^'^ 
instinct  of  crowinL'  ou  the  narf  of  .V''^''®  P^"'^U»'08  that  the 

Z  llv'-  '"'^"'^'^  "^  nian-and  especially  of  savaCS- 
usuaUy  is  as  compared  with  the  sum  of  othei-  inH.^nn^ 
prgamcand  inorganic;  we  must  remember  the  time  whch 
in  any  case  is  required  for  the  modification  of  an  insSct 
and  we  must  have  proof  that  the  instinct  which  Ts  now  ?i' 
umus  m  sonie  percentage  of  cases,  has  long  been  hToWv" 
injurious  m  a  large  percentage  of  cJp^     t  ot!r     7     ^^Sn^y 

iuriou.^pffp^f''''S-  ?  ?^  ^mndix  also  alludes  to  the  in- 
ins  inct  311  ""^-'^  frequently  attend  the  exercise  of  the 
instinct  of  migration  in  certain  animals.    Thus  he  savs  ihl 

Ptfnnf ''"r*  ^"'^-^^P^^^  ^^  ^f"^^'  ^°d  of  the  Passe'n'er 
Pigeons  lu  America  is  detrimental  to  the  animals  in  romf 

TwTu  a  ^Z'r%T  r'''  ^^^owedTbttTo?  prly 
lumbers  of  hnfhf  /  7^'"'  "^^  remember  the  enormoui 
numoers  ot  both  kinds  of  animals  which  thus  con<n-prratp  j 
cannot  see  that  any  difficulty  remains ;  forTot  on^TthJ 


i   '       I; 

H    ; 

t,   ! 


I 


1. 

;  *  t 

j     , 

,!  1  ■■  i 

i 

282 


MENTAL  EVOLUTION  IN  ANIMALS. 


iM'  '    . 


rercfcntage  of  individuals  destroyed  in  itself  small,  but  I 
doubt  whether  it  13  much  large,  than  would  be  the  case  if 
tliese  multitudes  of  ammnls  were  segregated  over  a  very  much 
wider  area.  A  stronger  case.  I  thiSkris  afforded  by  thTof 
^«::r  "^'"""^  ^"'  ^'^"'°"  '  shall  consider  it  at 
Since  Mr.  Darwin  wrote  his  remarks  on  this  subiect 
which  are  presented  in  the  Appendix,  further  statements  with 
reference  to  it  have  been  published.    These,  therefore,  I  sTaU 

Mr.  Crotch,  who  has  had  the  opportunity  of  observing  the 
phenomena  for  a  number  of  years,  thus  briefly  gives  Ms 
account  of  the  facts,  so  far  as  they  concern  us        *^  ^    ""^  ""^ 

"  T^^f  Lemmings  (^vliich  are  Httle  rodents)  certainly  do 
not  visit  my  part  of  Norway  at  any  recurring  period  of 
J  ears  ;  but  every  third  or  fourth  year  they  may  be  expected 
with  tolerable  regularity,  though  in  variable  numbers.^ Thus 
It  is  quite  probable  that  some  migrations  may  have  so  far 
escaped  notice  as  to  give  rise  to  the  old  idea  that  they  took 
place  every  tenth  year.  ''^ 

fln.r  ^Jl'^^.T.^''^'  however,  always  directed  '.westwards ;  and 
thus  the  theory  that  they  are  caused  by  deficiency  of  food 
fails  so  far,  that  these  migrations  do  not  take  place  in  a 
southerly  direction  by  which  a  larger  supply  might  be  ob- 
tained. M.  Guyne  (loc.  cit.)  suggested  that  the  course  fol- 
lowed  was  merely  that  of  the  watershed.  Ho  /ever,  this  runs 
east  as  weU  as  west,  and  follows  valleys  which  often  run 

Tr  uedlr'l  ^''  ^''''^'f'  '^  iBiles,  whereas  the  route 
pursued  by  the  Lemming  is  due  west.    At  aU  events  this  is 

m.r^V'  T°''''5'  "^^^'^  *^^y  ^^^^«^«e  ^^^  broadest  lakes 
failed  with  water  at  an  extremely  low  temperature,  and  cross 

«  Sl^T^^  ""^P^^  *°^^®^*«  ^^d  the  deepest  vaUeys 
With  no  guiding  pillar  of  fire,  they  pass  on  through  a 
wilderness  by  night ;  they  renr  their  families  on  their  journey, 
and  the  three  or  four  generations  of  a  brief  subarctic  summS 
serve  to  sweU  the  pilgrim  caravan.  They  winter  beneath 
more  than  six  feet  of  snow  during  seven  or  eight  weary 
months;  and  with  the  first  days  of  summer  (fo?  in  those 
regions  there  is  no  spring)  the  migration  is  renewed.  At 
length  the  harassed  crowd  thirned  by  the  increasing  attacks 
ot  the  wolf,  the  fox,  and  even  the  reindeer,  pursued  by 
eagle,  hawk  and  owl,  and  never  spared  by  man  himself  yet 


INSTINCTS  APPARENTLY  DETRIMENTAL  TO  THE  SPECIES.  283 

stiU  a  vast  multitude,  plunges  into  the  Atlantic  Ocean  on 
the  first  calm  day  and  perishes  with  its  front  still  pointincr 
westward.  No  faint  heart  lingers  on  the  way,  and  no  sur- 
vivor returns  to  the  mountains.  Mr.  R.  CoUett,  a  Norwe^dan 
naturahst,  writes  that  in  November,  1868  (quoted  bv  Fille- 
burg,  infra),  a  ship  sailed  for  fifteen  hours  through  a  swarm  of 
Lemmings,  which  extended  as  far  over  the  Trondhjemsfiord  as 
the  eye  could  reach."* 

^     Such,  according  to  Mr.  Crotch,  axe  the  facts,  and  the  follow- 
ing are  the  hypotheses  which  have  been  propounded  to  ex- 
p  am  them.    Mr.  Wallace  suggestsf  that  natural  selection  has 
played  an  important  part  in  causing  migration,  by  givincr  an 
advantage  to  those  animals  which  enlarge  their  breeding^'area 
by  travel    To  this  view,  as  applied  to  the  lemming^  Mr 
Crotch  objects  that  the  animal,  "  it  is  true,  always  breeds 
during  migration ;  but  if  none  return  or  survive,  it  is  difficult 
to  say  what  becomes  of  the  fittest."     His  own  theory  is  a 
remarkable  one.     «  There  is,"  he  says,  "  a  solution  of  this 
5'T  1  ^J  involving  a  subject  of  the  deepest  interest,  and 
which  led  me  to  spend  two  years  in  the  Canaries  and  adjacent 
islands.     I  allude  to  the  island  or  continent  of  Atlantis 
It  is  evident  that  land  did  exist  in  the  North  Atlantic  Ocean 
at  no  very  distant  date.    .    .    .     I3  it  not  then  conceivable 
and  even  probable,  that  when  a  great  part  of  Europe  was 
submerged  and  dry  land  connected  Norway  with  Greenland 
the  lemmings  acquired  the  habit  of  migrating  westward  for 
the  same  reasons    which  govern  more  familiar  migrations  ? 
.    ;    .    It  appears  to  me  quite  as  likely  that  the  impetus 
ot  migration  towards  this  continent  should  be  retained  as 
that  a  dog  should  turn  round  before  lying  down  on  a  ru<T 
merelv   because  his    ancestors  found  it  necessary  thus  to 
liollow  out  a  couch  in  the  long  grass." 

In  a  later  papert  he  combats  by  the  aid  of  charts  the 
popular  theory  "  that  these  migrations  follow  the  natural 
declivities  of  the  country,"  and  then  proceeds  to  add  "  It  is 
very  remarkable  that  the  average  depth  from  Norway  to  Ice- 
land aoes  not  exceed  250  fathoms,  with  the  exception  of  a 
deep  and  narrow  channel  of  682  fathoms  at  14°  W  This 
probably  represented  the  old  Gulf  Stream;  and  if  this  were 
60,  the  lemmings  did  wisely  to  migrate  westwards  in  search 

•  Linn.  Soc.  Jour    vol  xiii,  p.  30,  et  seq.        f  Noture,  vol.  x,  p.  459. 
{  Lmn.  isoc.  Jour.,  vol,  xiii,  p.  I57,  et  seq. 


fjjl 


•'■  I 


284 


MENTAL  EVOLUTION  IN  ANIMALS 


!>  m 


'"i   . 


ofita  genial  influence.  As  little  hv  liffTo  ^t, 

on  the  land  the  qa,r^ooV     f  ^  ^'^^^  *^®  ^^^^^  encroached 

they  do  to  this  day  »       "^^"^'^^^«  ^«^d  remain,  as  in  fact 

BentCl::TClZZr!^r^^  '^^'^'^''^  ^^  -other 
these  migrations'nlm^M^^^^ 

Museum,  Claristiauia.*  His^dew  i,  flTo?  '  ^^^  ^""'^""'^^^^ 
production  is  excessive  imiuJn/  '%^^^^^?  years  when  re- 
hunger,  as  well  as  bv  "f?r     .  "^^5  f  individuals  are  led  by 

by  ?hi;™  c  tJ  overfloTJS  's^^  r.'-  P— J 

home,  and^preid  out^' fve J  an  arr^  f-^^^''  ^^"^'^"^ 
larger  than  obtains  in  an  vothp?  off  r  ^^- ''  ^^^^^iderably 
circumstances."  As  breed  n.  Ly  '^''''l  ""'^^^  ''"^^^^ 
wandering,  in  cases  where  L  two  or  t^ ''''  throughout  the 
the  production  of  youn.  has  been  pI/""  ^^^ceeding  years 
are  incessantly  pushed  t'nwnrri.fl  excessive,  «  the  masses 
the  migration^beCmes  an Tver^^^^^^^^^  {he  fells;  and 

remote  portions  of  the  coun?rv  ."  i?^  9f  the  lower  and  far 
penetrate  further  in  search  Jftlr.-''^'^'^""^^  ^^'^^^^^ 
habits  (and  which  are  cambl«  .f  '  .'"'^^^^^  *°  ^^^^i' 

subsistence)  uitS  thev  «£  i  ^^S^g  them  a  permanent 
in  some  other  manner  "         '^^^^'^  ^^  ^^'  ''^  or  destroyed 

as  w';faa\\f LSS^^^  -  the  subject, 

think  we  may  most    Sel"i  ^^  ^^  ^^^vvs,  I 

The  most  imporTant  pdnt^of  dfffp''^"^'^ "''  *"  ^^^  latt;r. 
and  Mr.  ColLt  has  ^rXence  foT''  ^f  ^^^en  Mr.  Crotch 
while  Mr.  Crotch  states  thItTh.  •  T'"'^'''''  ^^  ^^^t.  For 
wards  without  reference  to  tt  "."^rations  are  made  west- 
Mr.  Collett  is  emphat"?n  fay Lg  tha't  " thJ  w  ^.-^^^ry. 
place  m  the  direction  of  thevluLlnd  ttt  '-^^""f  take 

out  from  the  plateauxianrStLn-T^H''  '""^  ^T'^ 
IS  an  end  of  Mr  Crotch'cTi?!^.        5  1,    ^^  this  is  so,  there 

to  explain  would  be  wht  tlI\^''^  *^'  ^^^>^  ^^^^^^ty  left 
they  still  conSe  on  their  nn^  f  ^'"^"^^^^^  ''^'^  the  sea, 
multitudes  by  drowning  ThPn  '°"''f  ^^P'"^^  ^^  thei; 
not  far  to  seek  For X^V  3  • '  ^""f  T  *°  this,  however,  ia 
in  their  wanderings  thev  ooT.  ''^  ^'^'^'  ^"^  '""'^  that  when 

iw». -Soc.  Ji,i,r.,  vol.  xiii,  p.  327,  e«  ^^2. 


MIGRATION. 


285 


lemming  furnishes  aiy  diStv  to  t,h»  ?i?  ""^"'."'"'  "^  *''« 
over  and  above  that  whLh  faVmiS^^d  tX  ,7°'""^^ 
more  important  case  of  migration  in^Z.!.  i  ^  .?  '"^er  and 
tion  of  which  I  shaU  now  proceed    ^         '  ^  '^'  '=°''^"««'- 

Migration. 

migration  are  to  bfE  in  th«  ^'f  ?'  *^  '"^"^^  of 
is  l-nfflcient  to  refer  to  °^Cm:i^?Pn^*™',?'^  I  ^i-k  it 

concerning  the  migraLs  Tc  abfflTsf  4°'  ^r^"^ 
pillars  (238-40^  thono-h  ^c  v.«„  T  A^^,"  ^^"^-^-2)*  and  Cater- 
following  re^iabW^^^^^^^^  ^  ^^^  ^^^  the 

« Colonies  and  India."  '        ""^    ^  ^^^^^  ^^'o^    the 

would' l7d5?ke  ryrX'trnT^^^'T^'  .^-^  -^-P^^^-^ 
to  the  "Eangitikei  lSvoL^e»W^nl^?^'^^^^^^^ 
local  railway  a  few  days  aC    In  thl      ^i.^^^  ,P^^^^  «^  ^h? 
kina.  New  Zealald   S  alv  of ^^'^!;^^^^^?^    «f  Tura- 
thousands  strong  was  marohi^«  !  ^^^^'P'^^f.^^'  hundreds  of 

new  field  of  oats'wTnXtig  cre'alon^^Th'^^^^^-  ! 
the  creeping  vermin   x^t^v^  «t    v^  T  i.    ^«-     thousands  of 

engine,  aSd^sudd™"  tle^traTn  ?:!  {o'a'd"^''  °'  *^ 
examination  it  was  fiund  tteLThee  °  of  the  „''°P-  v°5 
become  so  ffreasv  that  ti^^,,  i     f  "^"*^^^^  ^'  tiie  engine  had 

vancing-thrcTuld  not  Jp'th?  rdls'^'Tir'"  ^'H  ^^ 
eng  ne-driver  nrocured  mSJiLj   .        _,  ■       8"""^  =«id  the 

the%rain  madeTS  starf  te  ,>n  "  S\""=  '^"^'  ™4 

stoppage  caterpilla^  in  thlsaL'  C  T\  *'",?«™S  *« 

engme  and  overran  the  carri'agi  „sMe  andtt-'"  °™'  "'^ 

-nTi^oSr^"  MiiraS -^.^  -r 
orrnro::?™to"i]e%rn7r-n  '^^^^^^^^ 

south  to  north  The  column  wh,v{^  f"^^  ^^"^^"^  ^">^ 
reet  broad,  „ew  low  ^Zl^fd  ^.t^  t^^'^ 


III 


'J 


'     I  ^ 


I'    ': 


ii. 

1 

J: 

1 

1) 
1    , 

I  i  ■ 

1 

286 


MENTAL  EVOLUTION  IN  ANIMALS. 


'11 


'Uli 


The  caterpillar  of  this  species  is  not  gregarious.  Professor 
Bonelli  also  describes  a  migration  similar  in  all  respects 
including  locality,  except  th^t  it  lasted  longer— the  insects 
covering  the  flowers  at  night  and  proceeding  on  the  iourney 
by  day.  -^ 

Immense  swarms  of  migratory  Dragon-flies  have  been  at 
times  observed,  the  most  remarkable  case  being  one  that 
occurred  in  May,  1839,  and  which  seems  to  have  extended 
over  a  great  part  of  Europe.  The  insects  flew  at  a  height  of 
100  to  150  feet,  and  seemed  to  follow  the  direction  of  the 
rivers.* 

Many  species  of  Fish  are  known  to  migrate  regularly  for 
purposes  of  spawning,  such  as  the  herring,  sahnon,  &c.,  and 
also  to  find  water ;  f  while  among  Eeptiles  the  most  remark- 
able instance  seems  to  be  that  which  is  furnished  by  the 
Turtles  which  visit  Ascension  Island  to  deposit  their  eggs. 
How  the  animals  can  find  this  comparatively  small  speck 'of 
land  in  the  midst  of  a  vast  ocean  is  very  unaccountable.     I 
have  recently  written  to  Professor  Moseley  upon  the  subject, 
and  in  reply  he  says,   "No  man  without  proper  modern 
means  of  finding  latitude  and  longitude  could  reach  either 
Tristan  or  Ascension;    and    it    is    especially  difficult  for 
animals  whose  eyes  cannot  bp  raised  above  the  sea-level,  and 
to  whom,  therefore,  the  islands  are  visible  for  a  comparatively 
small  radius  only.    Merchant  skippers  have  several  times 
been  unable  to  find  Bermuda,  and  on  return  baffled  have 
reported  the  island  gone  down."     But,  as  Professor  Moseley 
adds,  "  It  is  Just  possible  that  the  animals  do  not  retire  far 
from  the  land  after  all,  but  hang  about  unobserved,"  I  think 
It  is  undesirable  to  enter  into  any  discussion  where  the  facts 
are  still  of  an  uncertain  character. 

Among  Mammals,  from  whales  to  mice,  we  meet  with 
many  inigratory  species,  but  it  is  among  Birds  that  the 
propensity  is  most  prevalent.  Indeed,  a  very  competent 
authority  on  all  matters  pertaining  to  ornitholo^ry  has  said  in 
the  new  "  Encyclopaedia  Britannica :  "  "  Every  bird  of  the 
northern  hemisphere  is  to  a  greater  or  less  degree  migratory 
in  some  part  of  its  range.  Such  a  conclusion  brings  us  to  a 
BtiU  more  general  inference—viz.,  that  Migration,  instead  of 

*  For  a  full  account  see  Weissenbome,  Loundoun't  Mag.  Nat.  Ristt 
N.S.,  vol.  iii.  ' 

t  See  Animal  Intelliffince,  218-50. 


MIGRATION. 


287 


of  the 


indicated  the  animals  in  which  the  W,w   •''™"8  ™^ 

Migration  at  the  beafnn^n!  ^  f^  *  ?^^^^^  ^  remarks   on 
.»f^^.e.thate,^atSSs  tt^{l„:! 

rdSt^^HoTntS"''-^' '^ '''-^^^  P^^^^^^^^ 
species  in  ie  J^^  tT:^::^-^^^^^^^-^ 

of  kno^ng  the  diin  In  S  i^St  •"^'  ^""^  ^  ^^"^ 

ana.,i2"™"^y^-^r^^^^^^^  n,a,  ^ 

ani.a,saSr„-2--^^;^^^^^^^^^ 

crigfn^te.tS'^'A'i''  ^TSs'^ht  ^""""1^  "'^ 

ancestors  Of  miaratorvflnimJio,  ^f^^^  ^«   *ha<^  the 

or  want  of  Zf^lyT^^ZZT''^^  ^"^^^'  ^^  ^^^^ 
we  may  weU  believe  that  fhl  L  ^^?'^^'^' '  "^^^  in  time 

become  an  instinctxve  mssion  "  asT,^?^'^  ''"^'^i^"^  ^^"^^ 
cated  sheep  in  Spain  In  Z'..?  /v.^'^^'?  ^^^^  ^^^^^sti- 
be  used,  and  iftZ  course  of  '"1  ^''^''  '^'  ™Ss  would 
the  land  over  which  thevTw  in  f\^  successive  generations 
to  become  slowirsubmeT.ed  the  it'''  fT\"  J°""^^>^«  ^«^'« 
unaltered,  and  thus  ^81^,1/^!      f.  ""^  ^'^^*  ^^^^^  "^^^^^^ 

•  Professor  Newton,  P. E  S    Ar^      '-   -,  »u 
the  main  facts  of  migration  as  regaSa  biras?  '  ''^  ^''^  *  S^"*^  '•««*^' "« 


•  i 


11 


in  > 


m 


'I      :^ 


it 


'l  I 


\ '  I 


288 


MENTAL  EVOLUTION  IN  ANIMALS. 


>.l       t 


pendently  arrived  at  by  Mr.  Wallace.  It  is  only  now  that 
Mr.  Darwin's  views  upon  this  subject  are  published,  although 
they  were  committed  to  writing  as  they  appear  in  the 
Appendix  between  twenty  and  thirty  years  ago.  Mr.  Wallace 
however  enunciated  substantially  the  same  views  in  a  letter 
to  "Nature"  in  1874  (Oct.  8),*  from  which  I  shall  quote  w 
extenso,  not  only  for  the  purpose  of  showing  the  coincidence 
to  which  I  have  alluded,  but  also  because  I  think  that  the 
additional  element  which  Mr.  Wallace  mentions— i.e.,  the 
separation  of  breeding  and  subsistence  areas — ^is  a  most  im- 
portant one. 

"  Let  us   suppose  that  in  any  species  of  migratory  bird, 
breeding  can  as  a  rule  be  only  safely  accomplished  in  a  given 
area ;  and  further,  that  during  a  great  part  of  the  rest  of  the 
year  sufficient  food  cannot  be  obtained  in  that  area.     It  will 
follow  that  these  birds  which  do  not  leave  the  breeding  area 
at  the  proper  season  will  suffer,  and  ultimately  become 
extinct ;  which  will  also  be  the  fate  of  those  which  do  not 
leave  the  feeding  area  at  the  proper  time.     Now  if  we  sup- 
pose that  the  two  areas  were  (for  some  remote  ancestor  of  the 
existing  species)  coincident,  but  by  geological  and  climatic 
changes  gradually  diverged  from  each  other,  we  can  easily 
understand  how  the  habit  of  incipient  and  partial  migration 
at  the  proper  season  would  at  last  become  hereditary,  and 
so  fixed  as  to  be  what  we  term  an  instinct.     It  will  probably 
be  found  that  every  gradation  still  exists  in  various  parts  of 
the  world,  from  a  complete  coincidence  to  a  complete  separa- 
tion of  the  breeding  and  subsistence  areas ;  and  when  the 
natural  history  of  a  sufficient  number  of  species  in  all  parts 
of  the  world  is  thoroughly  worked  out,  we  may  find  every 
link  between  species  which  never  leave  a  restricted  area  in 
which  they  breed  and  live  the  whole  year  round,  to  those 
other  cases  in  which  the  two  areas  are  absolutely  separated. 
The  actual  causes  that  determine  the  exact  time,  year  by 
year,  at  which  certain  species  migrate,  will  of  course  be  diffi- 
cult to  ascertain.     I  would  suggest,  however,  that  they  will 
be  found  to  depend  on  those  climatic  changes  which  most 
affect  the  particular  species.     The  change  oi  colour,  or  the 
fall  of  certain  leaves;    the  change  to  the  pupa    state   of 
certain   insects;    prevalent  winds   or  rains;    or  even  the 

•  Captain  Hutton  also  foreshadowed  these  views  in  1872 1   lee  Trais, 
New  Zealand  Inst.,  p.  235. 


MIGRATION. 


289 


i    ;'    W 


tt"rj!.encT"^"^^  ^'  ^^^  -^^  -^  water,  .ay  all  have 

sicai;^^Lt7etr^  besides  being  intrin- 

enquiries  made  by  Mr  Darwfn  wV  I  V°^  '"^PP'^'^  ^^°»i  the 
is  a  general  relatLslip  betwe '  opf  ^^^^«^r^  ^^^^<^  ^^^^re 
is  independent  reason  LcSudeh'T  ''^'"1'  ^^^^^  ^^ere 

assu'r^;iil^fi^^  tS^  tMs  theory  .Lestwo  important 

of  direction,  and  second  that  a  nn  l"""^'  ^  "^''^  ""'^^"'^  ««"«« 
the  particular  directZ  to  t  .  'a  •""'^f '"  knowledge  of 
certain  that  the  younTc^^^^^^  for  It  is 

its  parents)  canno^t  be  guire^nS.^  \"S^^"^  '^''' 

means,  and  it  is  asserted  hi  fi.  ^"''^Jo^^^ey  by  any  other 
of  many  other  ;;.V'^^£^^^^  theVung 

separately,  the  first  is  no  more  than  !  'L  ''/'.'TP^^^^'^ 
accountable  though  the  factTol  t!      'V^^l^^t  of  fact,  un- 

accurate  sense  of  dlect t  Satrv  bin /'  ^^ '^^^'.  ^  ^-^ 
possess,  and  it  is  probablv  k«  ?  ^  i"*^?  unquestionably 
"homing"  faculty  which  is  shown  'k  ^'^^  ''  '^'^  ''''^^^^^ 
animals,  and  also,  as  mJ  DamlnTnl.  ^  "^^7  domesticated 
I  could  iill  ppges  wi7h  iftLTwS  Vr' ^^ '""""^  ™^^- 
all  parts  of  the  world  describini^  5  ^'?  '"'"^^^^  ^^^^^^ 
cases  of  the  display  of  thTsfocfltvb'v  7  ^'''  remarkable 
i    J        tms  laculty  by  dogs,  cats,  horses,^ 

Je^wSl^h^if^SLVrje"^  ?:i^""?  ^  *^e  onl,  fact  I  W 

work  entitled  T/^e  ^aturaliJinR^ZVn  I  '  *^'°,''y"  M""-  "^^-dis  in  his 
fcn-er  i^haradj-iu.  rnar^JaZf—Ve:"^!'-  ?'*,*^^  °^%nitory  golden 
tudes  (b^^t  without  ever  alightingCtLTonnn  ''^!^*^'  [^  countless  multi- 
seen  passing  over  the  islands  on  the^r  ^^f,"'""'?*'^  «o"th,  while  they  are  never 
fact  that  the  two  journevs  are  token  h.?^  J*'"™*'^  °°'^^-  ^ow,  if  i^s  I 
encountered  by  thl  abovf  theory  ^'Lt^asMTn  "T''  '  ^^^^^^^^  -°"Jd  bj 

^J^thern  joui^ey.  althou^gh  Z  2S  SSeHe^iSo^Xrhrerp: 

t  See  Temminck,  Man.  d'Orn  o^  2  ,•,•;  t  ^  j 
f  tiert«  t«  i^«;.o^e.  On  the  other  WlLl'  ^T?^"'  -P"  ^'"^'  "^"^  Seebohm 
•those  who  have  had  no  instruction  do  nT""^' *^** '"  ^^^'^'^^^  «f  swallows 
f «  «een  to  be  led  by  those  whose  aae  and  «  '"•^™*"'  ^""^  *be  young  birl 
mnvTf  °';fc".'^"'^  *^dds  that  L  Xood  aXZ"',  ^^"^  ^^^"^  knowledge 
pany  the  old  birds  in  their  migration  '•?*  is  ?n^^''^f  ^'^t*^"  ^^^te  to  accom- 
•  .  .  .  they  perish  the  victims  of  thJ^'  '°  *^^*  *bey  reach  matunly 
f  I  W:  *^^-/-'^ble  to  folW  the  r  ;;r  S:^??:'  ^°?  ''  *^«  '-'^^  S^ 
t  I  We  one  instonee  of  .  eat  returS^  ^^ Sf^sZL't^Oon ^ 


I     ., 


m 


'If 


M  i 


I 


:'ii 


i 


290 


MENTAL  EVOLUTION  IN  ANIMALS. 


'    JJ   i 


I'        • 


p' . 


tv  #1  • 


asses,  cows,  sheep,  goats,  and  pigs ;  but  as  so  many  similai 
cases  are  already  on  record,  I  ieel  it  is  needless  to  add  to  the 
number.     The  remarkable  fact  is  that  the  animals  are  able 
to  find  their  way  back  over  immense  distances,  even  though 
the  outgoing  journey  has  been  made  at  night,  or  in  a  closed 
box ;  so  that  it  is  truly  upon  some  sense  of  direction,  and 
not  merely  upon  a  memory  of  landmarks,  that  they  must 
rely.     Moreover,  it  is  certain  that  in  many  cases,  if  not  as  a 
general  rule,  the  animals  on  their  return  journey  do   not 
traverse  the  exact  route  which  they  had  taken  in  the  out- 
going journey,  but  take  the  "  bee-line  ";♦  so  that,  for  instance, 
it  the  out-going  journey  has  been  made  over  two  sides  of 
a  triangle,  the  return  journey  will  most  probably  be  made 
over  the  third  side.     One  instance,  the  account  of  which  I 
have  received  from  a  correspondent  in  Australia,  is  of  suffi- 
cient interest  in  this  connection  to  quote.     "  A  pair  of  horses 
were  sent  many  hundred  miles  round  the  Australian  coast  by 
ship ;  as  they  did  not  like  their  new  quarters,  they  started 
back  by  land ;  but  after  returning  230  miles  they  were  pulled 
up  by  a  peninsula  on  the  coast,  where  they  were  eventually 
recovered.     They  did  not  attempt  to  retrace  their  steps  to 
clear  this  difficulty ."t 

Huddersfield,  a  distance  of  two  hundred  miles.  A  still  more  remartable  case, 
however,  was  published  by  Mr.  J.  B.  Andrews  in  Nature  several  years  ago 
(vol.  viii,  p.  6).  The  Archduchess  Marie  Regnier  passed  the  winter  of  1871-2 
at  the  Hotel  Victoria,  in  Mentone,  and  while  there  took  a  fancy  to  a  spaniel 
belonging  to  the  landlord,  M.  Milandri.  In  the  spring  of  1872  she  brought 
the  dog  with  her  by  rail  to  Vienna.  Not  long  afterwards  it  reappeared  at  the 
hotel  in  Mentone,  having  thus  run  a  distance  of  nearly  a  thousand  miles.  On 
arriving  it  died  of  fatigue  and  was  buried  in  the  hotel  gardens,  where  a 
monument  now  commemorates  the  performance.  Mr.  A.  W.  Howitt  writing 
to  Nature  from  Victoria  at  about  the  same  time  (vol.  viii,  p.  322)  gives  a 
number  of  cases  of  horses  and  cattle  finding  their  way  home  over  greater  or 
less  distances,  and  I  specially  allude  to  his  communication  because  he  says 
that  in  some  of  the  cases  the  return  journey  was  made  after  a  considerable 
lapse  of  time — months  and  even  years. 

*  This  is  an  American  term  which  I  employ  because  in  itself  showing 
the  observed  regularity  of  the  fact  as  regards  bees— it  being  the  custom  to 
find  wild  hives  of  honey  by  catching  several  bees,  and  letting  them  go  again 
from  different  places.  The  insects  under  these  circumstances  make  straight 
for  their  hive,  so  that  by  obsen'ing  the  point  where  several  "bee-linea" 
intersect,  the  honey  seekers  are  able  to  find  the  hive. 

1 1  may  here  also  quote  an  observation  by  Mr.  Darwin  to  the  same  effect :— • 
•'  I  sent  a  riding-horse  by  railway  from  Kent  via  Yarmouth,  to  Freshwater  Bay, 
in  the  Isle  of  Wight.  On  the  first  day  that  I  rode  eastward,  my  horse,  when 
I  turned  to  go  home,  was  very  unwilling  to  return  towards  his  stable,  and  he 
eeveral  times  turned  round.    This  led  me  to  make  repeated  trials,  and  every 


MIOKATIOlf. 


291 


pose  of  the  hypo7esi'"at„:eTbyT^:u:"tr',  *V^- 
that  the  return  journev  is  dnp  fn  t  ^  ^^"ace*  to  the  effect 
perceived  durin«  the  out  "n^nc,  •  ^  ^^^"^oj'y  of  the  odours 
serving  as  land  marks     Tltw   ''T"'^'  <^^^«e  odours  thus 

only  two  hypothZs  ope?  !>  t  -^  '^'"'^'  *'  ""'  '^"'"  "'" 
First,  it  ha's%eertho'^'gh  pLw/^^^^^^^^  "^^1  ^^^  ^^^^«- 
endowta  with  a  special  sense  enablLthLr'^'  "'"^  ^' 
magnetic  currents  of  fh^  To  fi  ^"^^iing  them  to  perceive  the 

by  a  compasfTere  is  no  n'h'"^  f '°  ^"^^^  ^^^"^«^1^««  ^s 

to  this  hyUes^but  as"     f  Xl  /SSf  ?  ^"^^'"^^ 
we  may  disregard  it       rur       v"0"y  aestitute  of  evidence, 

animals  are  able  to  keen  an  un'."n^  "'^'''  ^^P°'^^^^«  ^«  '^^^ 
and  curves  taken  in  the  01?^^-''°"'  ''^''^^'  ^^^^e  turns 

general  imp^ssU^^^STeS^'^r'  T  ^^^^^^  ^ 
substantiated  by  the  faof  fW  ^Vr  ^^'^  hypothesis  ia 
savage  man  is  certain! vpL*^'/' •¥'•  ^^^^^»  observes, 
and  a  friend  of Tv  own  ^^^^^^      with  some  such  faculty 

who  has  spent' Z;7eaMl7foff  ^T^'  ^^^^^^ 
America,  informs  me  that  etpn  n    -r  '?'   ^"^  P^'^^"^^  of 

accustomed  to  sLh  ^i^'mtve  LbTs  o^^^^^^  "'^"  ^?.«" 

faculty  in  a  decree  of  nPrfppHn«  <?  7  "®'  acquires  this 

savages.  Hralso  informer!  ^i.^'J^  comparable  with  that  of 
assignable  reason  thl  SLp  ff'  ^^^'^^^onally,  without  any 
leading  to  a  d  stiVsen^^^  ^^^^-^< 

seen  a  hunter  thus  L3to\ln^''''l'Vi"''^  ^^  ^^« 
nervousness,andwhen  at5ast  bp  .1  7^^^f  condition  of 
leadership  of  his  comr,anion  ,^^,  ^^^f  oned  himself  to  the 
own  sense  of  dLcS  he  fp l  ^^^^^d  entirely  on  their 
going  the  wrong  way^  But  on  ^"''^^1^  ^^^^  '^'y  ^«r« 

Of  the  trunk,  ^^^r::^'^^  ^^s^^ 

the  direction  whence  L  had  been  b^SfTX  T  ^*  ^«  ^^'^^^^^  ^-w 
from  Yarmouth  to  Freshwater  i^  Tr^^,  a  ^"""l^  ^^^^  *^at  ^^^  last  stage 
had  been  ridden  by  my  groom  •  butt  n  "^"^  '°'''^  ^"^  ^^o^g  t^s  road  S 
m  this  direction  "Wt^reZl  ^£  p  3607  TJ^  t'^^;^^-"^  -'^^  to  return 
•  ^a^Mrc,  loc,  cit.  '  ^'    °"''     ®^^  ^^"^  i^^a^wre,  viii,  p.  322. 


n 


■■  'I 


■    i 
if  i; 


til 


292 


MENTAL  EVOLUTION  IN  ANIMALS. 


II 


\l'  I 


seemed  to  have  turned  round  him  as  a  centre.  In  this  con- 
nection I  may  quote  the  following  passage  from  a  letter 
Fvd  vm  J"""^  years  ago  by  Mr.  Darwin  in  "Nature" 

''  The  manner  in  which  the  sense  of  direction  is  sometimes 
suddenly  disarranged  in  very  old  and  feeble  persons,  and  the 
teeling  of  strong  distress  which,  as  I  know,  has  been  experi- 
enced by  persons  when  they  have  suddenly  found  out  that 
they  have  been  proceeding  in  a  whoUy  unexpected  andwron<T 
direction  leads  to  the  suspicion  that  some  part  of  the  braiS 
IS  speciahzed  ior  the  function  of  direction.     Whether  animals 
may  not  possess  the  faculty  of  keeping  a  dead-reckoning  of 
their  course  in  a  much  more  perfect  degree  than  man  ^  or 
whether  this  faculty  may  not  come  into  play  on  the  com- 
mencement of  a  journey,  when  an  animal  is  shut  up  in  a 
basket,  I  will  not  attempt  to  discuss,  as  I  have  not  sufficient 
data.      He  also  alludes  to  the  case  of  Audubon's  pinioned 
wild  goose,  which  showed  a  very  determined  impulse   to 
migrate  at  the  proper  season,  but  mistook  the  direction  and 
went  due  north  instead  of  south. 

Lastly   I  may  quote  the  following  from  Dr.  Bastian's 
work  on  the  Brain.* 

"On  this   subject,  G.  C.  Merrill,  writing  from  Kansas, 
says  '^— 

.,  !^}}^^^  learned  from  the  hunters  and  guides  who  spend 
their  hves  on  the  plains  and  mountains  west  of  uf  that  no 
matter  how  far,  or  with  what  turns,  they  may  have  been  led, 
in  chasing  the  bison  or  other  game,  they,  on  their  return  to 
camp,  always  take  a  straight  line.  In  explanation,  they  say 
that,  unconsciously  to  themselves,  they  have  kept  all  the 
turns  in  their  mind.' 

"  Eeferring  to  his  travels  in  the  State  of  Western  Virtrinia 
Mr  Henry  Forde  ('Nature,'  April  17,  1873,  p.  463)  writes 
as  tollows :— '  It  is  said  that  even  the  most  experienced  hun- 
ters of  the  forest-covered  mountains  in  that  unsettled  region 
are  liable  to  a  kind  of  seizure— that  they  '  lose  their  heads ' 
all  at  once,  and  become  convinced  that  they  are  goin»  in 
quite  the  contrary  direction  to  what  they  had  intended,°and 
that  no  reasoning  nor  pointing  out  of  land-marks  by  their 
compamons,  nor  observations  of  the  position  of  the  sun,  can 

•  Brain  as  an  Organ  of  Mind,  p.  215,  where  sea  also  for  cases  of  way- 
nnding  m  animals.  ' 


MIGRATION, 


293 


n;  or 
com- 


feeling  eometiLs  ceases  suddeffvo?  f'^"'' '''™'*'  ^''« 
gradually.     Colonel  TnH™  J„  i,^  Tir       '  ""y  *•""■  awny 

Par  Wesl'  l"  ^^^^  Zt^fS^'llT''  ''  ""'' 
upon,  and  occasionally  demomlizTn.  old  °f /f  ^^"«^  «^^^'»g 
prairie  travellers.     Indian  cSfpn"'.  i  experienced 

G  Pnflin  AT-f  ■  "u"in  cniets  all  concurred  in  asqiirin» 
^.  Uatlin  ('  Life  amongst  the  Indians '  n  ()a\  f^of "  ^^^""^g 
a  man  is  lost  on  the  Drairie/^p T„  f-f^)^^^\'^^GneyeT 
that  he  invariably  tu^rto  th^^pf  f  ?•  ^  "''^''  ^"^  ^^'^'^ 
the  author  adds   '  I S,  hi  !  '  ,f  '^^"^'^  ^^"^"1^^^  fact/ 

quent  proofs/ "'       ^"^^  ^''°"^'  ^^^^^^  ^°^^^in«<^^l  by  subsel 

facuftrboilt' men'^ndln"'^  ^T""^"^^  -  *^-  h--«- 
can  be  in  a  positSn  to  «!      T'^''  ^''  "^^^"^'^^  before  wS 

than  admitLrifasVmSr  nfi"?  Tvf'  ^^'^  ''^^'^^  '^  ^^ 
which  have  be^en  made  so  f«r  -  ?  °°^^  experiments 

John  Lubbock  on  the  Ln/f  5-^  ^"^  ^'^^'''  ^^^  <^bose  of  Sir 
(to  which  I  Shan  aterele'nS^'^^^^^^^  Hymenoptera 
more  recently  been  publiE  by' M  f2  "'^^^^^  ""''' 
perimented  upon  the  Hymenoptera  A,  Vi.  ,  f^'°  ^''■ 
author  believes  thnf  hp  will  Pf;      ^^  ^^e  last-named 

sion  by  mean    of  hJs   expeSnttl^"^  '^'"^^^  ^•^"^^- 
should  make  a  few  reLaZ"pr£m'  '^  """"^^  ^^^^  ^ 

prisoned  for  some  TtlneeFnl  J  "^"""^  ^^""^  ^^"«  i^^- 
box  and  carried  them  a^^,nS  """"^^''T'^^'  then  rotated  the 
direction,  after  whthhTreleS;  ?'''"''  ^^  '^^  °PP°^^*« 
that  when  the  distance  to  wt  ?b  h  ^  ''''''^'-  ^^  ^°""d 
much  as  three  kinmPfrp«o^  ''^  ^^''  '^^'^  ^^^^en  was  as 
very  eonsSer'ble   (^^^^^^^^^^  the  rotation  was 

rotated  in  various  r,]^L.ai.  ^  ,^.^  ^^  ^  ^liug  and 
certain  percental  of  Z  h  '^""''^^  P°^"*^  ^^  ^^e  route)  a 
differencfSfi  the  bees  wpJ^'V"'^.^^^^^  ^'  ^^^eio 
in  a  thick  wood  neither  didTJl'"''^  'It""  "P^^  «P^^«  «r 
the  outgoing  iournevwprP  Jf^ 

a  circuitous  ^cCe^^rorthp?™'^  '°  "  '''"'»^^  ^^^^  «^-i« 
uxve.    -^rom  these  experiments  M.  Pabre  con- 

•  Muveaus  Souvenir.  Entonologi^ue,,  1882,  pp.  09-123. 


^U 


?H 


IVIII 


1!    I 


!f|):-;; 


■1    ill- 

MIMf^^^ 

■  t 

Bl^^^^^': 

!    ( 

1' 
ill 

■■■■MsBrK** 'jar.  >  • 

•    1       ' 

H^»p: 

^HpMi^'^i 

^^KmSei  •' 

If 

294 


MENTAL  EVOLUTION  IN  ANIMALS. 


eludes  that  the  sense  of  direction  cannot  depend  upon  any 
process  of  dead-reckoning.  At  the  suggestion  of  Mr.  Darwin 
he  also  tried  the  effect  of  attaching  a  magnetized  needle  to 
the  thorax  of  a  bee  ;  but  the  bee  having  succeeded  in  getting 
nd  of  the  encumbrance,  he  did  not  repeat  the  experiment. 

Now,  although  the  observations  with  the  rotating  box  are 
no  doiibt  very  interesting,  they  do  not  appear  to  me  to  sustain 
the  definite  conclusion  that  the  sense  of  direction  is  not  due 
to  a  process  of  dead-reckoning.     It  is  of  course  impossible 
to  suppose  that  the  bees  could  retain  a  register  of  all  the 
turns  to  which  they  were  submitted  in  the  sling,  and,  there- 
fore, if  it  were  certain  that  they  found  their  way  home  by 
means  of   their  sense  of   direction,    I  should  agree   with 
M.  Fabre  in  concluding,  once  for  all,  against  the  theory  of 
dead-reckoning.     But  there  is  no  evidence  to  show  that  the 
bees  which  found  their  way  home  did  so  by  means  of  their 
sense  of  direction.     It  is  quite  possible  that  they  found  their 
way  home  simply  from  their  knowledge  of  land-marks ;  for 
the  distance  to  which  they  were  taken  was  only  three  kilo- 
metres, and  it  is  known  that  the  hive-bee  will  go  tbr^p  ^-iraes 
that  distance  in  its  ordinary  foraging  excursions.*    Moreover, 
the  fact  that  only  a  comparatively  small  number  of  the  bees 
succeeded  in  returning  (about  22  per  cent.),  is  suggestive  of 
the  explanation  that  these  were  the  only  ones  which,  durin<T 
the  random  flight  of  the  whole  number  in  sundry  directions', 
happened  to  encounter  land-marks  with  which  they  were 
familiar.     I  am  therefore  inclined  to  feel  that  any  sense  of 
direction  which  existed  in  these  insects  may  very  well  have 
been  rendered  useless  by  these  experiments,  and  yet  that  the 
results  of  the  experiments  might  have  been  exactly  those 
■which  M.  Fabre  describes. 

Keturning.  however,  to  the  case  of  migration,  I  think  it  is 
not  very  improbable  that  the  sense  of  direction  may  be  greatly 
assisted  by  observing  the  direction  of  the  sun  with  reference 
to  the  appropriate  line  of  flight.  It  is  true  that  many  migra- 
tory birds  fly  at  night ;  but  in  this  case,  even  if  the  moon  is 
not  available  to  steer  by  instead  of  the  sun,  during  much  of 
the  night  the  directions  of  sun-set  and  sun-rise  are  clearly 
indicated  by  the  light  of  the  sky;  and  it  appears  that  on 
very  dark  and  cloudy  nights  migratory  birds  are  apt  to  become 

•  Scfl  Ariitnul  IntdUgence,  p.  150. 


MIORATIO». 


298 


confused*    The  possibility  thus  suj7p:ested  rccoives,  I  think, 

somo  countenance   from   the  foUowing  fact.     In  "Animal 

Intelligence  "  I  recorded  a  number  of  observations  which  had 

been  made  by  Sir  John  Lubbock  on  the  sense  of  direction  as 

exhibited  by  ants.     These  experiments  yielded  results  of  a 

most  definite  nature,  and  thus  led  Sir  John  to  conclude  that 

ants  are  endowed  with  the  sense  of  direction  in  a  singular 

degree.     Subsequently,  however,  he  has  found  (accidentally 

m  the  first  instiince)  that  in  all  these  experiments  the  ants 

lound  U;oir  way  by  observing  the  direction  in  which  the  li<dit 

was  falling ;   so  that,  as  long  as  the  source  of   light  was 

fituuouary,  no  mutter  how  many  times  he  turns  them  round 

upon  a  rotating  table,  when  the  rotation  ceased  tliey  knew 

tlieir  road  to  and  from  the  hive  as  well  as  they  did  before  the 

rotation ;   whereas,  if  the  source  of  light  were  shifted    the 

insects  at  once  became  confused  as  to  their  bearin"s   even 

though  not  rotated  at  all.f    Now  if   ants  thus  habitually 

guide  themselves  by  observing  the  direction  in    /hich  the 

light  18  taUing  (i.e.,  the  position  of  the  sun),  I  do  not  see  why 

migratory  birds  should  not  be  assisted  by  similar  means. 

This,  however,  I  only  put  forward  as  a  conjecture  The 
fact  that  migratory  birds,  like  many  other  animals,  are  in 
some  way  able  to  hold  a  true  course  in  order  to  reach  a  par- 
ticular locality,  is  a  fact  which  confessedly  we  are  not  able  to 
explain.  But— and  this  is  the  most  important  point  for  us— 
our  inabihty  to  explain  this  fact  in  the  present  state  of  our 
intormation,  is  no  objection  to  the  theory  of  instinct  on  which 
we  are  engaged.  We  cannot  doubt  that  the  fact  admits  of 
some  explanation,  and  when  we  certainly  know  what  this 
explanation  is,  we  shall  first  be  able  to  ascertain  whether  the 
faculty  of  way-finding  is  or  is  not  compatible  with  the 
toregomg  theory  of  the  evolution  of  instinct. 

Let  us  turn  now  to  the  second  of  the  two  assumptions 
above  alluded  to  as  necessary  in  order  to  embrace  the  facta  of 
migration  under  the  theory— viz.,  the  assumption  that  some 
at  least  among  migratory  birds  must  possess,  by  inheritance 
aione,  a  very  precise  knowledge  of  the  particular  direction  to 

t„Vl!f  ^®°  ^'•ofessor  Newton  in  Nature,  vol.  xi,  p.  6,  who  says,  "Dark  cloudy 
mghtfl  seem  to  disconcert  the  travellers.  On  such  nights  the  attention  o? 
others  besides  myself  has  often  been  directed  to  the  cries  of  a  mixed  muEudo 
SL  w^>),  °T'''°^  """/  ^^^  (Cambridge)  and  other  tov^Tis,  apparently  ata 
low  whither  to  proceed,  and  attracted  by  the  light  of  the  street  lamps.'^ 
t  isee  Journ.  Linn.  Soc,  1883.  ^ 


i  ii 


M^l 


I 
I 

1.1 
1 

! 
1 

-■■.<■■•!• 


VI 


■!     I 


Uh      i 


'I: 


206 


MENTAL  EVOLUTION  IN  ANIMALS. 


be  pursued.    It  is,  without  question,  an  astonishing  fact  that 
a  young  cuckoo  should  be  prompted  to  leave  its  foster-parents 
at  a  particular  season  of  the  year,  and  without  any  truide  to 
showthe  course  previously  taken  by  its  own  parents;  but 
this  IS  a  fact  which  must  be  met  by  any  theory  of  instinct 
which  aims  at  being  complete,     Now  upon  our  own  theory  it 
can  only  be  met  by  taking  it  to  ue  due  to  inherited  memory.   I 
confess  to  me  it  seems  incredible  that  many  hundred  miles  of 
landscape  scenery  should  constitute  an  object  of  inherited 
memory,*  to  say  nothing  of  long  stretches  of  ocean ;  but  the 
case  is  not  quite  so  hopeless  as  to  require  so  extreme;   a 
hypothesis.  •  Wheu  we  say  that  upon  our  theory  the  youncr 
cuckoo  must  be  supposed  to  find  its  way  on  its  first  journey 
by  inherited  memory,  we  need  not  necessarily  affirm  that  this 
IS  the  memory  o2  a  landscape.    As  I  have  said  in  the  pre- 
vious paragraphs,  we  do  not  yet  know  what  it  is  that  guides 
the  course  of  migratory  birds  in  general;  but  whatever  this 
""^^i,  ''i?*  ^^^  scarcely  be  the  appearance  of  the  country  over 
which  they  pass,  seeing  not  only  that  the  distances  are  so 
great  and  that  two  hundred  or  three  hundred  miles  of  ocean 
may  separate  one  piece  of  country  over  which  they  travel 
irom  a:iother,  but  also  that  the  journeys  may  be  taken  by 
night.     Of  what,  then,  is  the  inherited  memory  on  which  the 
young  cuckoo  (if  not  also  other  migratory  birds)  depends  ? 
We  -can  only  answer,  Of  the  same  (whatever  thi:-  may  be)  as 
that  upon  which  the  old  birds  depend.     When  we  certainly 
know  what  this  is,  we  shall  first  be  able  to  ascertain  whether 
It  IS  incompatible  with  the  theory  of  evolution  to  suppose 
that  It  can  be  an  object  of  hereditary  memory.     Thus,  for  the 
sake  of  example,  let  us  suppose  that  the  old  birds  in  their 
outgoing  journey  guide  their  way  by  flying  towards  the  south 
wind  (as  has  been  suggested  to  me  by  Mr.  William  Black, 
who  believes  that  swallows  always  start  against  the  south 
wind) ;  heredity  would  in  this  case  have  an  easy  task  in 
associating  the  warm  moist  breath  of  this  wind  with  a  desire 
to  fly  against  it.     Of  course  I  only  adduce  tliis  suggestion  in 
order  to  show  how  simple  the  mere  question  of  heredity 
might  become,  if  once  we  knew  the  means  whereby  migratory 
birds  m  general  find  their  way.     The  only  difference  between 
the  faculty  of  homing  and  the  instinct  of  migration,  so  far  as 

l«p!^^'''!  ^^^"^  "^^l  ^'■'.*  ^^'^"ced  by  Canon  Kingsley  (Nature,  Jan.  18, 
lSfa7),  and  has  since  been  independently  suggested  by  several  writers. 


INSTINCTS  OF  NEUTER  INSECTS. 


297 


the  matter  of  way-finding  is  concerned,  seems  to  me  to  be 
this — that  in  the  case  of  the  young  cuckoo,  and  perhaps  also 
in  that  of  certain  other  migratory  birds,  the  animals  know 
their  way  instinctively,  or  without  even  one  lesson.  But  if 
we  could  ascertain  upon  what  it  is  that  the  faculty  of  homing 
depends  (which,  be  it  observed,  is  not  an  instinct,  seeing  that 
its  occurrence  is  the  exception  and  not  the  rule,  even  in  the 
species  which  exhibit  it),  we  might  very  probably  get  a  clue 
to  explain  the  manner  in  which  heredity  has  been  able  to 
work  up  this  faculty  into  the  instinct  of  migration. 

No  doubt  this  discussion  is  most  unsatisfactoiy,  and  the 
reason  is  that  we  are  so  much  in  the  dark  about  the  facts. 
All,  therefore,  that  I  have  attempted  to  do  is  to  show  that,  in 
the  present  state  of  our  information,  the  migratory  instinct 
cannot  fairly  be  quoted  as  a  difficulty  in  the  way  of  our 
theory  of  the  formation  of  instincts  in  general.  And,  in 
order  to  give  emphasis  to  this  statement,  I  may  allude  to' the 
general  facts  already  mentioned— viz.,  that  the  migratory 
instinct  is  both  variable  and  graduated,  that  it  is  occasionally 
exhibited  by  domesticated  animals,  and  that  the  sense  of 
direction  on  which  it  depends  is  a  very  general  one  among 
animals,  if  not  also  in  savage  man ;  for  all  these  facts  tend  to 
show  that  whatever  the  causation  of  the  migratory  instinct 
may  be,  it  has  probably  been  proceeding  upon  the  lines  of 
evolution  in  general. 


f! 


,)  >■  ,  ;[j  It 


Instincts  of  Neuter  Insects, 

Mr.  Darwin  has  pointed  out  a  serious  difficulty  lying 
against  his  theory  of  the  origin  of  instincts  by  natural  selection" 
aiid  one  which,  as  he  justly  remarks,  it  is  surprising  that  no 
one  should  have  previously  advanced  against  the  well-known 
doctrine  of  inherited  habit,  as  taught  by  Lamarck.  The 
difficulty  is  that  among  various  species  of  social  insects,  such 
as  bees  and  ants,  there  occur  "  neuter,"  or  asexual  individuals, 
which  manifest  entirely  different  instincts  from  the  other 
or  sexual  individuals,  and,  as  the  neuters  cannot  breed,  it  is 
difficult  to  understand  how  their  peculiar  and  distinctive 
instincts  can  be  formed  by  natural  selection,  which,  as  we 
have  seen,  requires  for  its  operation  the  transmission  of 
mental  faculties  by  heredity.  The  difficulty  is  increased  by 
the  fact  that  among  the  termites  and  many  species  of  anta 


II, 


;-^ 


298 


MENTAL  EVOLUTION  IN  ANIMALS. 


Whfch  Jfr  '-^'^  r^"'  °^  """<^^^«  °«^"^"  i«  *^«  S^^e  nest. 
.^  n=f w  ""ii^^^  ^^'^  °°^  ^«°<^^e^  ^oth  in  structure  and 
in  instincts.  The  only  possible  way  in  which  this  difficulty 
can  be  met  is  the  way  m  which  it  has  been  met  by  Mr.  Darwin 
VIZ.  by  supposing  "that  selection  may  be  applied  to  the 
th^nL''  'V^?  if  dividual."  "  Such  f Jith  may^Uplaced  in 
nZrZtl  °^«^^^'\*^^on  .^hat  a  breed  of  cattle  always  yielding 

?ormprS.'''^''f  f/"^'"^^  l'"S  ^°^°^  ^^"Id,  it  is  probable,  he 
lormed  by  carefully   watching  which  individual  bulls  and 
cows,  when  matched,  produced  oxen  with  the  longest  horns- 
and  yet  no  one  ox  would  ever  have  propagated  its  kind :» 
and  similarly,  of  course,   with  regard"^  to   the  instincts   of 
neuters     Otherwise  stated,  we  may  regard  the  nest  or  hive 
as  Itself  an  orgamsm  of  which  the  sexual  insects  and  the 
several  castes  of  neuters  constitute  the  organs  ;  and  we  mav 
then  suppose  natural  relation  to  operate  upon  this  organism 
«,^nnnZ  >  ;  somewhat  in  the  same  way  as  we  habitually 
suppose  It  to  operate  upon  the  "social  organisms"  or  com- 
munities of  mankind.     No  doubt,  when  ca?efully  considered 
the  analogy  between  a  hive  and  an  organism,  or  even  between 
a  mve  and  a  social  community,  is  not  a  close  analogy  so  far 
as  the  modus  operandi  of  natural  selection  is  concerned  •  for  in 

individuals,  while  m  the  other  case  there  is  no  such  great 
contrast  between  different  classes  of  a  human  community  as 
that  which  obtains  among  the  different  castes  of  an  insect 
community.      The  root  of  the  question  really  consists  Tn 
whether  or  not  it  is  possible  to  suppose  that  natural  selection 
may  operate  upon  specific  types  as  distinguished  from  indivi- 
dual members  of  species.     During  his  life-time  I  had  the 
advantage  of  discussing  this  question  with  Mr.  Darwin  and 
I   ascertained   from  him  that  it  had  greatly  occupied   his 
thoughts  while  writing  the  "Origin  of  Species;"  but  that 
hnding  it  to  be  a  question  of  so  much  intricacy,  he  deemed  it 
unadvisable  to  enter  upon  its  exposition.     It  would  occupv 
too  much  space  were  I  to  attempt  such  an  exposition  here, 

^hl.i.  7-!^^'''^'i?  V^^  subject  only  because  I  desire  to 
show  that  It  IS  really  this  general  question  which  is  involved 
in  the  case  of  the  special  difficulty  with  which  we  are  now 
concerned.  On  some  future  occasion  I  intend  to  argue  this 
general  question,  and  then  I  shall  hope  to  mitigate  the  force 
oi  this  special  difficulty.     I  may,  however,  point  to  one  fact 


INSTINCTS  OF  THE  SPHEX. 


299 


which  Mr.  Darwm   has  observed,  and  which  is  of  much 
importance  a,s  indicating  that  the  different  castes  of  neuters 
have  arisen  by  degrees,  and  therefore  presumably  under  the 
influence  of  natural  selection.     This  fact  is  that,  when  care! 
lully  searched   for,  neuters  presenting  more  or  less  weU 
marked  gradations  of  structure  between  one  caste  and  another 
may  be  occasionaUy  found  in  the  same  nest*    On  the  whole 
therefore,  I  conclude,  with  regard  to  this  particular  case  of 
difficulty,  that  it  is  not  so  formidable  as  to  exclude  the 
explanation  furnished  by  the  hypothesis  of  natural  selection 
supposing  that  we  have  already  accepted  this  hypothesis  as 
explanatory  of  other  and  less  difficult  cases. 

Instincts  of  the  Sphex. 

Several  species  of  this  division  of  the  Hymenoptera  dis- 
play what  I  think  may  be  justly  deemed  the  most  remarkable 
instincts  m  the  world.     These  consist  in  stinging  spiders 
insects,  and  caterpillars  in  their  chief  nerve-centres,  in  con- 
sequence of  which  the  victims  are  not  killed  outright,  but 
rendered  motionless;  they  are  then  conveyed  to  a  burrow 
previously  formed  by  the  Sphex,  and,  continuing  to  live  in 
their  paralyzed  condition  for  several  weeks,  are  at  last  avail- 
able as  food  for  the  larvae  when  these  are  hatched.     Of  course 
the  extraordinary  fact  which  stands  to  be  explained  is  that 
ot  the  precise  anatomical,  not  to  say  also  physiological  know- 
ledge which  appears  to  be  displayed  by  the  insect  in  stin-ina 
only  the  nerve-centres  of  its  prey.     The  following,  so  fa'^r  as 
is  at  present  known,  are  the  main  features  of  this  verv  sur- 
prising case.  ^ 

The  same  species  of  Sphex  always  preys  upon  the  same 
species  of  victim.     When  the  victim  is  a  spider^he  instS 
ot  Its  assailant  dictates  that  a  single  sting  shall  be  given  in 
the  large  ganglion  where,  in  the  case  of  the  spider,  most  of 
the  central  nervous  matter  is  aggregated.     When  the  victim 
IS  a  beetle,  the  Sphex  which  preys  upon  it—there  are  ei-ht 
species  which  prey  upon  two  genera— first  throws  the  insect 
upon  Its  back,  then  embraces  it  and  plunges  the  sting  through 
the  membranes  between  the  first  and  the  second  pairs  of  lee?  • 
tfie  stmg  thus  strikes  the  main  nerve-centre,  which  is  unusually 
agglomerated  in  beetles  of  this  genus.    When  the  prey  is  a 

•  See  Origin  of  Species,  231-2. 


1 1 


I;  # 


{    v 


.HI 

-I  'il 


V\\\ 


300 


MENTAL  EVOLUTION  OF  ANIMALS. 


cricket,  the  insect  is  thrown,  as  in  the  previous  case,  upon  its 
back,  and  while  holding  it  down  with  her  mandibles  firmly 
fastened  upon  the  last  segment  of  its  abdomen,  her  feet  on 
the  sides  holding  down  the  body  of  the  cricket-the  anterior 
feet  holding  down  the  long  posterior  legs  of  the  prey,  and  the 
hind  feet  holding  back  the  mandibles,  so  as  to  prevent  these 
trom  biting,  and  at  the  same  time  making  tense  the  mem- 
branous junction  of  the  head  with  the  body-the  Sphex  darts 
her  stmg  successively  into  three  nerve-centres ;  first  into  the 
one  below  the  neck  which  she  has  stretched  back  for  the  pur- 
pose, next  into  the  one  behind  the  prothorax,  and  lastly  into 
the  one  lower  down.     A  cricket  thus  paralyzed  will  live  for 
six  weeks  or  more.     When  the  prey  is  a  caterpiUar,  a  series 
ot  six  to  nine  stmgs  are  given,  one  between  each  of  the  seo-- 
mentsof  the   body  beginning  from  the  anterior  end:  the 
dibles*^  partially  crushed  by  a  bite  with  the  man- 

Now  so  far  as  the  spider  and  the  beetle  are  concerned   I 
do  not  see   much  difficulty  presented  by  the  facts  to  our 
theory  of  the  formation  of  instincts.    Tor  as  both  the  larcre 
nerve-centres  of  the  Spider  and  the  sting  of  the  Sphex  occSr 
upon  the  median  line  of  their  respective  possessors,  if  the 
stinging  of  the  ganglion  were  in  the  first  instance  accidentally 
favoured  by  this  coincidence— which  appears  to  me  not  im- 
probable, seeing  that  the  nerve-centre  is  thus  the  most  likely 
place  for  the  stmg  to  strike,— it  is  evident  that  natural  selec- 
tion would  have  had  excellent  material  on  which  to  work  for 
tlie  purpose  of  developing  such  an  instinct  as  we  now  observe 
Again   m  the  case  of  the  beetle,  M.  Fabre  expressly  notices 
that  the  only  vulnerable  point  in  the  hard  casing  of  the 
animal  is  in  the  articulation  where  the  Sphex  th?usts  her 
sting;  so  that  there  is  nothing  very  remarkable  in  natural 
selection  having  developed  an  instinct  to  sting  at  the  only 

^ossible  ""^  ^^^  ^""^^  "^^^"^  '^'°^'°°  '^  mechanically 

But  the  case  is  certainly  very  different  with  the  cricket 
and  the  caterpillar;  for  here— or  at  least  in  the  latter  case— 
we  encounter  the  extraordinary  and  unavoidable  fact  of  an 
insect,    without  any    accidental   guiding    or    mechanically 

*  All  the  above  facts  are  taken  from  the  works  of  M.  J    H    Fabre 
&rthem.         ''^''"''  ''^'  ^""^  ''''^'  ^^^  ^^^  *^«  ^^'  to  observe  ij 


INSTINCTS  OF  THE  SPHEX. 


801 


imposed  necessity,  instinctively  choosing  a  number  of  minute 
points  in  the  uniformly  soft  body  of  its  prey,  with  an  appa- 
rently very  precise  knowledge  that  it  is  only  at  these  par- 
ticular points  that  the  peculiar  paralyzing  influence  of  its 
sting  can  be  exercised.     After  duly  considering  this  case   I 
must  candidly  say  that  I  feel  it  to  be  the  mJst  perplexing 
which  has  yet  been  brought  to  light,  and  the  one  which  il 
most  ditticult  of  explanation  upon  the  principles  of  the  fore- 
^i°'''f  J  i,®''^^-     ^^  /^'  however,  most  desirable  that  the  facts 
should  be  more  thoroughly  investigated,  for  it  might  then 
appear  that  some  clue  would  be  given  as  to  the  origin  and 
development  of  this  instinct.     So  far  as  our  information  at 
present  extends  I  can  only  suggest  that  this  origin  must  have 
been  of  a  purely  secondary  kind,  although  its   subsequent 
development  may  probably  have  been  assisted  by  natural 
selection     In  other  words,  so  far  as  we  have  any  means  of 
judging  1  can  see  no  alternative  but  to  conclude  that  these 
wasp-like  animals  owe  their  present  instincts  to  the  hioh 
intelligence  of  their  ancestors,  who  found  from  experience 
the  ettects  of  stinging  caterpillars  between  the  segments  of 
their  bodies,  and  consequently  practised  the  art  of  so  stino-ins 
them  till  It  became  an  instinct. 

v^'It'^^t^^®  ^^^^  y^^"*  °^  ^'^  li^®  I  had  some  conversation 
with  Mr.  Darwin  upon  this  matter,  and,  after  deliberatino- 
upon  It  for  some  time,  he  eventually  came  to  the  conclusion 
which  I  have  just  stated— as  will  be  at  once  apparent  from 
the  following  letter  which  he  wrote  to  me,  and  which  will 
serve  m  a  few  words  to  indicate  what  appears,  I  think,  to  be 
the  naost  probable  steps  by  which  these  singular  instincts  were 
acquired. 

"I  have  been  thinking  about  Pompilius  and  its  allies  — 
Wease  take  the  trouble  to  read  on  perforation  of  the  corolla 
by  Bees,  p.  425  of  my  «  Cross-fertilization,"  to  end  of  chapter 
i^ees  show  so  much  intelligence  in  their  acts,  that  it  seems  not 
improbable  to  me  that  the  progenitors  of  Pompilius  ori<Tinallv 
stung  caterpillars  and  spiders,  &c.,  in  any  part  of  their  bodies 
and  then  observed  by  their  intelligence  that  if  they  stunts' 
them  in  one  particular  place,  as  between  certain  segments  on 
the  lower  side,  their  prey  was  at  once  paralyzed.     It  does  not 
seem  to  me  at  all  incredible  that  this  action  should  then 
become  instinctive,  i.e.,  memory  transmitted  from  one  genera- 
tion to  another.    It  does  not  seem  necessary  to  suppose  that 


a 


!• 


'■■  -:) 


h  lit 


i ," 


I- 

i , 

I . 

!  ■■ 

•4 

303 


MENTAL  EVOLUTION  IN  ANIMALS. 


■11 


when  Pompilius  stung  its  prey  in  the  ganglion  it  irrtended  or 
knew  that  their  prey  would  keep  long  alive.  The  development 
of  the  larvae  may  have  been  subsequently  modified  in  relation 
to  their  half-dead,  instead  of  wholly  dead  prey ;  supposing 
that  the  prey  was  at  first  quite  killed,  which  would  have 
required  much  stinging.     Turn  this  over  in  your  mind,"  &c. 

Now  in  Chapter  XIV I  have  already  given  a  short  epitome 
of  the  facts  concerning  the  boring  by  humble-bees  of  holes  in 
corollas,  and  the  subsequent  utilization  of  the  holes  by  hive- 
bees.     It  will  be  remembered  that  the  connection  in  which  I 
there  alluded  to  the  facts  was  that  of  the  power  of  imitation 
by  one  species  of  the  habits  of  another — the  hive-bees  observ- 
ing that  the  humble-bees  were  saving  time  by  sucking  through 
the  holes  instead  of  entering  the  flowers.     But  the  point 
which  is  of  importance  in  the  present  connection  is  the  intelli- 
gence displayed  by  the  humble-bees  in  originating  the  idea, 
so  to  speak,  of  boring  the  holes.     For  close  observation  shows 
that  they  bore  the  holes  with  as  precise  an  appreciation  of 
the  morphology  of  the  flowers,  as  is  shown  by  the  Sphex  of 
the  morphology  of  spiders,  insects,  or  caterpillars.     Thus  in 
the  case  of  leguminous  flowers  they  bite  only  through  the 
standard  petal,  and  always  on  the  left  side  just  over  the 
passage  to  the  nectar,  which  is  larger  than  the  corresponding 
passage  on  the  right  side.     Therefore,  as  Mr.  Francis  Darwin 
observes,  "it  is  difficult  to   say  how  the  bees  could  have 
acquired  this  habit.     Whether  they  discovered  the  inequality 
in  the  size  of  the  nectar-holes  in  sucking  the  flowers  in  the 
proper  way,  and  then  utilized  this  knowledge  in  determining 
where  to  gnaw  the  hole ;  or  whether  they  found  out  the  best 
situation  by  biting  through  the  standard  at  various  points, 
and   afterwards  remembered  its  situation  in  visiting  other 
flowers.     But  in  either  case  they  show  a  remarkable  power  of 
making  use  of  what  they  have  learnt  by  experience."* 

Seeing,  then,  that  Hymenopterous  insects  are  certainly 
proved  by  these  observations  to  be  capable  of  marvellously  in- 
telligent appreciation  of  morphological  structure,  I  think  with 
Mr.  Darwin  that  these  observations  are  most  apposite  to  the 
case  of  the  Sphex.  There  is  not,  after  all,  so  very  much  more 
of  this  kind  of  appreciation  required  to  observe  the  effects  of 
stinging  a  caterpillar  between  its  segments,  than  to  hit  upon 

a  flower  and  biting  a  hole  on  the 
•  Nature,  Jan.  8,  ISy*,  p.  189. 


the  idea  of  going  outside 


FEIGNING  DEATH. 


303 


left  side  of  a  particular  petal,  just  over  the  spot  where  the 

«nif  T^f!2T^/^l''''u'  ^'  ^?  ^"  ^°"^^'     ^'^t'  ^«  I  have 
said,  I  leel  that  further  observation— especially  in  the  wav  of 

experiment-of  the  facts  is  required  before  we  should  be 
justified  in  giving  a  very  definite  opinion  upon  the  theoretical 
mterpi^tation  of  them.     All  I  can  say  is  that,  in  the  present 
state  of  our  information  upon  the  subject,  Mr.  Darwin's  view 
as  above  stated,  appears  to  be  the  most  probable  one  that 
can  be  taken     We  are  not  much  surprised  at  the  instinct  of 
a  i  erret  in  attacking  the  medulla  oblongata  of  a  rabbit,  or  at 
that  ot  a  Pole-cat  m  paralyzing  frogs  and  toads  by  injuring 
the   cerebral   hemispheres;*   and  in   both   these   cases-sS 
analogous  to  that  which  we  are  now  considering— the  instinct 
must  have  originated  by  intelligent  observation  of  the  effects 
ot  biting  these  particular  parts  of  the  prey.     But  neither  a 
terret  nor  a  pole-cat  is  a  particularly  intelHgent  animal,  so 
that  we  are  perhaps  too  ready  to  feel  surprise  at  the  pos- 
sibly  similar  degree  of  intelligence    displayed   by  in.^ects 
iS^als    ''''^  *o  the  most  intelligent  group  of  invertebmted 

Feigning  Death. 

It  is  a  matter  of  common  knowledge  and  wonder  that 
sundry  species  of  animals  belonging  to  different  orders  and 
even  classes,  manifest  the  instinct,  when  in  danger  of  feion- 
ing  death.  As  it  is  clearly  impossible  to  attribute  this  fact 
to  any  idea  of  death  and  of  its  conscious  simulation  on  the 
part  of  the  animals,  the  subject  becomes  one  of  importance 
for  us  to  consider.  I  shall  first  give  all  the  facts  that  I  have 
been  able  to  collect  with  regard  to  it,  and  then  proceed  to 
discuss  their  explanation. 

The  most  familiar  example  of  the  instinct  in  question  is 
furnished  by  sundry  species  of  insects  and  spiders,  many  of 
which  allow  themselves  to  be  slowly  dismembered  or 
gradually  roasted  to  death,  without  betraying  the  sliahtest 
movement.  "Among  fish,  the  captured  sturgeon  remains 
quiet  and  passive  in  the  net,  while  the  perch  feigns  death 
and  floats  on  its  back."t  According  to  Wrangle.J  the  wild 
geese  of  Siberia,  if  alarmed  during  the  moulting  season  when 

*  See  Animal  Intelligence,  p.  347. 

t  Couch,  Illustratio'.is  of  Instinct,  p.  199,  et  tea. 

I  Travels  in  Siberia,  p.  312,  Eng.  Transl. 


i     !  I 


i  V- 


3  r  ;  111 


304 


MENTAL  EVOLUTION  IN  ANIMALS. 


Ilii: 


/ 


they  are  unable  to  fly,  stretch  themselves  at  length  upon  the 
ground  with  their  heads  concealed,  so  as  to  feign  death  and 
deceive  the  sportsman.  According  to  Couch,  the  habit  is 
common  to  the  landrail,  the  skylark,  and  other  birds.* 
Among  mammals,  the  same  author  says,  "  The  opossum  of 
.North  America  is  so  famous  for  feigning  death,  that  its  name 
has  become  proverbial  as  an  expression  of  tliis  deceit  ;"*  and 
he  nariates  instances  of  the  same  fact  with  regard  to  mice, 
squirrels,  and  weasles.  The  testimony  on  the  subject  vvitli 
regard  to  wolves  and  foxes  is  so  abundant  that  I  do  not  think 
there  can  be  any  reasonable  question  concerning  its  accuracy. 
Thus  Captain  Lyon,  in  the  account  of  his  Polar  Expedition, 
says  that  a  wolf  caught  in  a  trap  which  was  set  by  Mr.  Griffiths, 
was  apparently  killed  and  then  dragged  on  board.  "  The  eyes, 
however,  as  it  lay  on  deck,  were  observed  to  wink,  whenever 
any  object  was  placed  near  them;  some  precautions  were 
therefore  considered  necessary ;  and  the  legs  being  tied,  the 
animal  was  hoisted  up  with  his  head  downwards.  He  then, 
to  our  surprise,  made  a  vigorous  spring  at  those  near  him ; 
and  afterwards  repeatedly  turned  himself  upwards,  so  as  to 
reach  the  rope  by  which  he  was  suspended,  endeavouring  to 
gnaw  it  asunder,"  &c. 

The  testimony  is  abundant  on  the  subject  of  foxes 
shamming  dead.  As  Mr.  Blyth  observes,!  "  a  fox  has  been 
known  to  personate  a  defunct  carcase,  when  surprised  in  a 
hen-house,  and  it  has  even  suffered  itself  to  be  carried  out 
by  the  brush  and  thrown  out  on  a  dungheap,  whereupon  it 
instantly  rose  and  took  to  its  heels,  to  the  astounding  dismay 
of  its  human  dupe.  In  like  mani^er  this  animal  has  submitted 
to  be  carried  for  more  than  a  mile,  swinging  over  the  shoulder 
with  its  head  hanging  downwards,  till  at 


length  it  has  very 
speedily  effected  its  release  by  biting," 

Similarly  Couch,  who  gives  a  number  of  instances  of  the 
fact,  summarizes  them  thus : — "  When  suddenly  surprised  by 
man,  he  has  been  known  to  assume  the  appearance  of  being 
dead,  and  has  suffered  himself  to  be  handled,  and  even  ill- 
treated,  without  betraying  any  signs  of  sensibility.  This  high 
degree  of  simulation  and  dissimulation  has  been  ascribed  to 
consummate  wisdom,  which,  when  a  better  means  of  escape 
did  not  offer  itself,  prompted  him  to  the  stratagem  of  feigning 


•  Loc.  cit. 


t  Loundoun's  Mag.  Nat.  Hist.,  N.S.,  vol.  i.  p.  6. 


i    IJJ 


FEIGNING  DEATH. 


upon  the 
ieath  and 
habit  is 
ir  birds.* 
tossum  of 
its  name 
it  ;"*  and 
'.  to  mice, 
ject  with 
not  think 
accuracy, 
cpeditioii, 
Griffiths, 
The  eves, 
whenever 
ons  were 
tied,  the 
He  then, 
lear  him ; 
so  as  to 
3uring  to 

of  foxes 
has  been 
sed  in  a 
irried  out 
:eupon  it 
g  dismay 
ubmitted 
shoulder 
has  very 

3S  of  the 
prised  by 

of  being 
even  ill- 
Phis  high 
bribed  to 
)f  escape 

feigning 

i  i.  p.  6. 


305 


to  be  incapable  of  defence  or  flicrht  until  Tip  }.nA  a- 
suspicion,  and  so  escaped  hostility  •  ""^  disarmed 

According  to  Jesse,  "  Snakes,  too,  will  nretend  fnh.A    a 
and  he  motionless,  as  long  as  thev  thTni  fl  ,     ^^^^' 

and  in  danger,  but  when  tVy  betCthat  allToeTh  '""''''f^' 
drawn,  and  they  are  out  of  peril  Xvlni  rf  ''^  '^'^^■ 
the  greatest  spe^d  into  the  neSt  hol^Tltf  '"^^  "^^' 

this  sters»  theTurr?f^?T'H^%~-^ed  for 
the  Corncrake'  rLtes  that  one  off f.      l-f^^^       ^^^''y  «^ 

pocket,  and  before  Inna  i'/u  ;^T^  ^■  ^  P"^  ^^  ^^to  his 
out.  and  it  seemed  Ss'  a  \1  ol'^^"&\^^^^^^^  ^^  ^-^^  ^t 
ground  and  retired  to  a  littlp  S  5  ^^®?  ^^'^  ^^  ^n  the 
in  about  five  mTnutes  ra^  it^  t^'"  ^^  T'^  '^'  ^"^  '^'^  it 
decamp  at  fulUpeed"  '^^  "^^'^^^^  ^°^^  '^^^^'  a^d 

tiseriryth'e  SmS  Zb^S^ T  V'"  ^^^^  '^  ^^  P- 

wiU  lie  as  if  ITwa^tin  Jjnr  «'.^'''  '^  apprehends  danger, 

into  the  sand  ktpinron^^^^^^^^^^^^  '^  «^"^  ^^^^ 

Hence,  it  appears  that  from  insects  upwards,  the  instinct 

but  as  under  the  circumstences  mentioned^wF^''r""^  feigning  death ; 
^o  die  (see  Animallntelli^ence  I  3qfi?  S  ^^^P^iants  very  often  actimli; 
buted  to  intentional  dece^ption  ^on Ihe  part  STw  ^''^"^^  T  "^  ^'  -''^^■ 
follows  I-"  Mr.  Cripps  has  related  to  m«^.  •  ,  ""™''^-  ^^«  ''^^e  is  as 
captured  elephant  w^a?  either  rlndere^  rnsdessTrf '°  "^"'^  \'^''-"-^ 
attendants  asserted, /«V»ed  rfeaM  in  !™il  7  •   ^  ^'^'^^''  o^,  as  the  native 

from  the  corral  as  us  J  between    wo  Ime  of^"'''  i^l^T  ^°°^-     ^'  ^^«  l^d 
far  towards  its  destination  ;XnnUf-  1!°    ' -"^  ^"J*  ^'"^^^  Proceeded 

hghted  it  refused  to  goon,  VndfinaufsantK^  ^°^  ^^^  ^^^'^^^^  ^'"^g 
less.  Mr.  Cripps  ordered  the  fasteniL  fJ^  ^  *^^  ^''''.^'^'  apparently  life- 
when  attempts  to  mise  it  had  failed  f.  ?  •  ""^T^^^  ^^^"^  »*«  legs,  and 
that  he  ordeW  the  rope  to  be  teten 'off  aST;''^  ^'^  ¥  ''^^^  ^^  ^«^  ^^ 
this  was  being  done  he  and  a  gentlemon  bv  tho  '  T'^"'  abandoned.  While 
against  the  body  to  rest.  Thfy  had  scarSlv  fT  \^^  accompanied  leaned 
ceeded  a  few  yards,  when  to  thSr  ««?  -if  '^'^^^  ^heir  departure  and  pro- 
utmost  alacrit;,  and  flS  towar^sThe  S^^T °*'  '^'  '^'^Y'''  ™««  -ith^^be 
Its  cnes  being  audible  long  Xr  it  D  di^  "'°i  ^'  ^^'^  ^P  "^  ^^  voice, 
forest."         *  *^  "'*'  "  ^^  disappeared  in  the  shades  of  thj 


H 


ii 


I    t 


II.' •   ;       t  1 

"I      n 


,  '11   .■.,>.' . 
f]'r     -^i 


mil 


306 


MENTAL  EVOLUTION  IN  ANIMALS. 


of  shamming  dead  occurs  in  most  if  not  all  the  classea  o! 
the  animal  kingdom.  The  suliject  therefore  demands  from 
us  serious  attention,  because  on  the  one  hand,  as  previously 
remarked,  it  is  obvious  that  the  idea  of  death  and  of  its 
conscious  simulation  would  involve  abstraction  of  a  higher 
order  than  we  could  readily  ascribe  to  any  animal,  and  on  the 
other  hand  it  is  not  very  easy  otherwise  to  explain  the 
facts. 

I  shall  first  of  all  quote  what  Couch  says  upon  the  sub- 
ject, as  he  is  the  first  author,  so  far  as  I  am  aware,  who  did 
not  at  once  take  it  for  granted  that  animals  consciously  feign 
death,  and.  who  also  supplied  a  reasonable  hypothesis  to 
account  for  the  facts.     He  says : — 

"  But  a  more  probable  explanation  is,  that  the  suddenness 
of  the  encounter,  at  a  time  when  the  creature  thought  of  no 
such  thing,  had  the  effect  of  stupefying  his  senses,  so  that  an 
effort  of  escape  was  out  of  his  power,  and  the  appearance  of 
death  was  not  the  fictitious  contrivance  of  cunning,  but  the 
consequence  of  terror.  And  that  this  explanation  is  the  true 
one  appears,  among  other  proofs,  from  the  conduct  of  a  bolder 
and  more  ferocious  animal,  the  Wolf,  under  similar  circum- 
stances. If  taken  in  a  pitfall  it  is  said  that  it  is  so  subdued 
by  surprise,  that  a  man  may  safely  descend  and  bind  and 
lead  it  away  or  knock  it  on  the  head ;  and  it  is  also  said  that 
when  it  has  wandered  into  a  country  to  which  it  is  a  stranger 
it  loses  much  of  its  courage  and  may  be  assailed  almost  with 
impunity."* 

"  A  similar  action  to  that  of  the  Fox  has  been  observed 
in  a  little  animal  to  which  it  is  not  common  to  ascribe  more 
than  an  ordinary  degree  of  cunning  or  confidence  in  its  own 
resources.  In  a  bookcase  of  wainscot,  impervious  to  light, 
certain  articles  were  kept  more  agreeable  to  the  taste  of 
mice  than  books,  and,  at  midday,  when  the  doors  were  suddenly 
opened,  a  mouse  was  seen  on  one  of  the  shelves ;  and  so 
rivetted  was  the  little  creature  to  the  spot  that  it  showed  all 
the  signs  of  death,  not  even  moving  a  limb  when  taken  into 
the  hand.  On  another  occasion,  on  opening  a  parlour-door,  in 
broad  daylight,  a  mouse  was  seen  fixed  and  motionless  in  the 
middle  of  the  room ;  and,  on  advancing  towards  it,  its  appear- 
ance in  no  way  differed  from  that  of  a  dead  animal,  excepting 
that  it  had  not  fallen  over  on  its  side.    Neither  of  these 

•  Mag.  Nat.  Hist.,  l^few  Ser.,  voL  ii,  p.  121. 


FEIGNING  DEATH. 


assea  ol 
(Is  from 
eviously 
d  of  its 
I  higher 
d  on  the 
luiu  the 

the  sub- 
who  (lid 
;ly  feign 
hesis  to 

Idenness 

ht  of  no 

that  an 

ranee  of 

but  the 

the  true 

a  bolder 

circum- 

subdued 

)ind  and 

3aid  that 

stranger 

ost  with 

observed 
ibe  more 
1  its  own 
to  light, 

taste  of 
3uddenly 
;  and  so 
lowed  all 
ken  into 
•-door,  in 
!ss  in  the 
s  appear- 
ixcepting 

of  these 


307 


creatures  made  an  effort  to  escape,  and  were  taken  „n  nf 

leisure;  nor  had  they  received  anVhurt  oT  h'jury  L  L* 

Boon  displayed  every  mark  of  being  alive  and  wdZ'  ^ 

It  would  be  as  easy  to  catch  a  Weasel  asleen  as  off  ,>- 

bemg  „h«t,  Puss,  deceived  by  its  app^fe    '  WeLn^ss  lail 

had  of  It  round  the  body  had  prevented  any  ?arl  er  eflbrt  at 

injury  ;  but  the  Weasel  can  ha?Sy  be  sunnosed  t^  h  J  K™' 
«ng  a  deception  all  the  ^Me^T^f  fnte^  ^^^.^ 

This  hypothesis  would  require  to  be  substinh'nfprl  w 
special  experiments  before  it  would  merit  urn^^^^^^^^^^^^ 
ance.  These  experiments  would  consist  in  allowin  'an  aniS" 
mmediatery  that  it  is  observed  shamming  dead  to  len"  Hs 
liberty,  and  to  watch  it  without  the  animal  knowing  th'itt 
being  observed.  If  it  were  then  to  continue  for  any  con  side 
able  time  motionless,  the  fact  would  tend  to  prove  Couoh'^ 

Tesence  of  dan  Jr  S  ?n  '  '"^'P^'^"^  the  passiveness  in  the 
inesence  or  aanger  clue  to  conscious  purpose.  I  once  thnimhf- 
that  I  had  myself  the  opportunity  of  trying  this  experS 
for  having  caught  a  wild  scjuinel  in  a  cloth  I  oterveSt  the 
animal  immediately  became  motionless.  TurniiJL  out  upon 
the  ground  and  concealing  myself  from  its  view  I  waiteda 

•  Illustrations  of  Instinct,  p.  125. 


H 


1^ 
I* 

Hi 


I  M^    i: 


W' 


808 


MENTAL  EVOLUTION  IN  ANIMALS. 


'        ( 


wild  animal  on  being  captured  may  be  sufficient  to  causa 
actual  death,  and  the  researches  of  Professor  Preyer  on  the 
hypnotism  of  animals  (conducted  long  after  Coucli's  book  was 
published  and  having  no  special  reference  to  the  present 
question),  showed  that  fright  is  a  strong  predisposing  cause 
of  "  Kataplexy,"  or  mesmeric  sleep  in  animals. 

This  allusion  to  Professor  Preyer's  researches  leads  me 
next  to  remark  that  he  ascribes  the  shamming  dead  of  insects 
to  the  exclusive  influence  of  kataplexy.  Having  observed 
the  potency  of  this  influence  in  producing  analogous  condi- 
tions in  the  neuro-muscular  systems  of  higher  animals— even 
as  far  down  the  series  as  the  cray-fish,  Avhich  were  made  to 
stand  upon  their  heads  whiie  in  the  hypnotic  state — it  was 
perfectly  logical  in  him  to  attribute  the  shamming  dead  of 
insects  to  the  same  cause.  And  his  reasoning  might  have 
been  greatly  strengthened  had  he  been  aware  of  the  import- 
ant facts  which  had  been  observed  by  Mr.  Darwin,  and 
which  are  now  given  in  the  Appendix.  These  facts,  it  will 
be  noted,  are,  that  there  is  no  species  of  spider  or  insect  of 
which  it  can  be  said  that  the  attitude  assumed  when  sham- 
ming death  at  all  closely  resembles  the  one  which  the  animal 
assumes  when  really  dead  ;  that  in  many  cases  this  attitude 
is  very  dissimilar ;  and  therefore  that  all  "  shamming  dead  " 
amounts  to  in  tliese  animals  is  an  instinct  to  remain  motion- 
less, and  thus  inconspicuous,  in  the  presence  of  enemies. 
And  it  is  easy  to  see  that  this  instinct  may  have  been  de- 
veloped by  natural  selection  without  ever  having  been  of  an 
intelligent  nature — those  individuals  which  were  least  in- 
clined to  run  away  from  enemies  being  preserved  rather 
than  those  which  rendered  themselves  conspicuous  by  move- 
ment. 

That  is  to  say,  it  is  easy  to  see  how  the  instinct  may  have 
become  developed  by  primary  means  ;  for  if  it  were  of  more 
advantage  to  an  animal  when  in  danger  to  become  motionless, 
and  therefore  inconspicuous  or  unattractive  to  enemies,  than 
it  would  be  to  ocek  safety  in  fliglit,  of  course  it  is  obvious 
that  in  such  cases  natural  selection  would  always  have 
operated  in  the  direction  of  producing  quiescence,  no  less 
than  in  other  cases  it  would  have  operated  in  the  direction  of 
producing  activity.  Now,  1  think  it  is  not  at  all  improbable 
that  "  kataplexy "  may  have  been  of  much  assistance  in 
originating,  and  possibly  also  in  developing,  this  instinct. 


FEIGNINO  DEATH. 


809 


continued  alonftL^!^.     1?  *°"°"  ''""'<'  "n™'  'ikely  b« 
state  occur  with  irrpnt  qii/1^-.»,„     i^iuuiuy,  so  as  to  make  the 

to  18  removed  •  *""'^  "^  ^'''""'"S  "i""'"- 

pec«.i^ties?f 'ol^rtiofofS™  ,f"^ 


Prinoiples  of  Cotl      :  VobabteS"  bS  *' 

of'^hth^iLrt^r  V '"™' ^^^  *^^^^^^ 

instinct     TW  ?    selection   has  constructed  this  particular 

themselves  to  be  pierrediitKiranJl^^^^^^^  ^'"'^'  "^'"  «"ff«' 

smallest  signs  of  terror"  JddB^lZt^f^?  P"*'"'  '''"'°"*  discovering  the 
kind  of  stupor  occasioned  by  terror  "th.  1  *""?  """'f' '''  "^^"^  ^^Pposel,  "  a 
when  the  object  of  terror  i7remov^  BnfT"'  ""f^*  °2*^/''  ^''^  ^  ^««°'er 
does  not  pass  off  immediatelv Tnnn  fi,-  !•*  ™^.^'*'  °^  ^'^^^^  ^^^  "stupor" 

long  as  the  katap  ectic  sSte liin  }^ ""'t*!^"  °^  ,**^°  «*™"1»«  '  it  '^sts  as 
on  its  back.     ^  ^  '*''^'  '°  '^^^'^''^  '^"^«'  8«^'li  M  the  owl  when  held 


310 


MENTAL  EVOLUTION  IN  ANIMALS. 


m 


lilr 


I 


ni: 


of  doubt,  and  even  if  the  phenomena  of  kataplexy  were  not 
available  for  natural  selection  to  seize  upon  for  the  purpose 
in  question,  there  can  be  no  doubt  that  other  materials 
might  have  been  so ;  for,  a  priori,  there  seems  to  be  at  least 
not  more  difficulty  in  developing  an  instinct  to  remain 
motionless  under  certain  circumstances,  than  in  developing 
one  to  run  away ;  and  as  a  matter  of  fact,  all  animals  which 
are  protectively  coloured  have,  either  as  cause  or  consequence, 
developed  their  instincts  in  the  former  directiou.  Therefore 
we  must  suppose  that  an  animal  which  was  not  sufficiently 
locomotive  to  find  safety  in  flight,  would  be  most  closely 
attended  to  by  natural  selection  in  the  direction  of  encourag- 
ing quiescence— and  this  whether  or  not  natural  selection 
were  provided  with  kataplectic  susceptibilities  on  which  to 
operate ;  kataplexy  alone  could  not  form  the.  instinct. 

So  far,  then,  the  subject  is  sufficiently  clear.     But  now, 
we  have  obviously  some  important  distinctions  to  draw.     Foi 
the  shamming  dead  of  a  highly  intelligent  animal  like  a  fox 
is  a  widely  difierent  matter,  psychologically  considered,  from 
the  shamming  dead  of  insects ;  so  that  an  explanation  v/hich 
might  be  held  fully  adequate  to  account  for  the  latter  might 
not  be  so  to  account  for  the  former.     Thus  while  I  have  no 
hesitation  in  regarding  the  fact  in  insects  as  due  to  a  non- 
•p    intelligent  instinct  developed  by  natural  selection  in  the  way 
just  explained,  I  cannot  see  how  this  could  well  be  the  case 
in  vertebrated  animals.    A  fox  would  never  have  so  good  a 
chance  of  escape  from  an  enemy  by  remaining  motionless  as 
ic  would  by  the  use  of  its  legs,  which  it  requires  a  fox-hound 
to  overtake.     Moreover  the  shamming  dead  is  here  far  from 
invariable,  and  so  is  not,  as  in  the  case  of  insects,  instinctive. 
Therefore,  although   I  did  not  fully  agree  with  Preyer  in 
assigning  the  universal  (instinctive)  quiescence  of  certain 
insects  when  alarmed  to  the  unassisted  influence  of  kata- 
plexy, I  think  that  the  occasional   (accidental)  display  of 
quiescence  by  wild  vertebrated  animals  under  similar  circum- 
stances tends  much  more  unequivocally  in  favour  of  his  view. 
For  here  the  action  is  not  universal,  or  even  usual ;  and  when 
it  does  take  place  it  must,  as  a  rule,  be  rather  detrimental  to 
the  animal  than  otherwise — seeing  that  the  whole  economy  of 
the  animal  is  here  adapted  to  rapid  movement.     Therefore  1 
think  that  in  the  case  of  Birds  and  Mammals  the  hypothesis 
of  Couch  already  quoted  is  the  most  reasonable — especially 


FEIGNING  DEATH. 


311 


if  we  supplement  it  with  our  knowledge  concernin*^  the 
recently  discovered  facts  of  kataplexy.*  ° 

On  the  other  hand,  not  to  shirk  a  difficulty,  I  have  some  re- 
markable  evidence  which  tends  to  show  that  certain  monkeys 
sham  dead  with  the  deliberate  purpose,  not  of  escaping  from 
enemies,  but  of  deceiving  intended  victims.  Here,  of  course 
there  can  be  no  terror  and  no  kataplexy,  so  that  if  we  accept 
the  evidence  of  the  fact  we  must  seek  for  some  other  expla- 
nation. ^ 

Thompson  gives  in  his  «  Passions  of  Animals  "  (pp.  455- 
7),  the  case  of  a  captive  monkey  which  was  tied  to  a  long 
upright  pole  of  bamboo  in  the  jungles  of  Tillicherry.    The 
ring  at  the  end  of  its  chain  fitting  loosely  to  the  slippery 
pole,  the  animal  was  able  to  ascend  and  descend  the  latter  at 
pleasure.     He  was  in  the  habit  of  sitting  on  the  top  of  the 
pole,  and  the  crows  taking  advantage  of  his  elevated  position, 
used  to  steal  his  food  which  was  placed  every  morning  and 
evening  at  the  foot  of  the  pole.     "  To  this  he  had  vainly 
expressed  his  dislike  by  chattering,  and  other  indications  of 
his  displeasure  equally  ineffectual;  but  they  continued  their 
periodical  depredations.    Finding  that  he  was  perfectly  un- 
heeded, he  adopted  a  plan  of  retribution  as  effectual  as  it  was 
ingenious.     One  morning  when  his  oormenters  had  been  par- 
ticularly troublesome,  he  appeared  as  if  seriously  indisposed  • 
he  closed  his  eyes,  dropped  his  head  and  exhibited  various 
other  symptoms  of  severe   suffering.     No  sooner  were  his 
ordinary  rations  placed  at  the  foot  of  the  bamboo,  than  the 
crows  watching  their  opportunity,  descended  in  great  num- 
bers, and  according  to  their  usual  custom,  began  to  demolish 
his  provisions.     The  monkey  began  now  to  descend  the  pole 
by  slow  degrees  as  if  the  effort  were  painful  to  him,  and  as  if 
so  overcome  by  indisposition  that  his  remaining  strength  was 
scarcely  equal  to  such  an  exertion.    When  he  reached  the 
ground  he  rolled  about  for  some  time,  seeming  in  great  a«ony 
until  he  fou-d  himself  close  to  the  vessel  einployed  to  Con- 
tain his  foot,  ,-hich  the  crows  had  by  this  time  well  nigh 
devoured.     There  was  still,  however,  some  remaining,  which 
a  sohtary  bird,  emboldened  by  the  apparent  indisposition  of 
the  monkey,  advanced  to  seize.     The  wily  creature  was  at 
this  time  lying  in  a  state  of  apparent  insensibility  at  the 

•  The  winking  of  the  wolf's  eye,  mentioned  by  Captain  Lyon,  would  be 
quite  compatible  with  a  certain  phase  of  the  hypnotic  state. 


ii  J- 
i 


5    ;N 


5'v 


312 


MENTAL  EVOLUTION  IN  ANIMALS. 


.f    1 


'   ' 


foot  of  the  pole  and  close  by  the  pan.    The  moment  the  crow 
stretched  out  his  head,  and  ere  it  could  secure  a  mouthful  of 
the  mterdicted  food,  the  watchful  avenger  seized  the  depre- 
dator by  the  neck  with  the  rapidity  of  thought  and  secured  it 
from  doing  further  mischief.     He  now  began  to  chatter  and 
grm  with  every  expression  of  gratified  triumph,  while  the 
crows  flew  round,  cawing,  as  if  deprecating  the  chastisement 
about  to  be  inflicted  on  their  captive  companion.      The 
monkey  continued  for  a  while  to  chatter  and  grin  in  triumph ; 
he  then  deliberately  placed  the  crow  between  his  knees  and' 
began  to  pluck  it  with  the  most  humorous  gravity.    When 
he  had  completely  stripped  it,  except  of  the  large  feathers  in 
the  pinions  and  tail,  he  flung  it  into  the  air  as  high  as  his 
strength  would  permit,  and  after  flapping  its  wings  for  a  few 
seconds,  it  fell  to  the  ground  with  a  stunning  shock.     The 
other  crows,  which  had  been  fortunate  enough  to  escape  a 
similar  castigation,  now  surrounded  it  and  immediately  pecked 
It  to  death.     The  animal  then  ascended  its  pole,  and  the  next 
time  his  food  was  brought,  not  a  single  crow  approached  it." 
I  have  quoted  this  case  although  it  sounds  well  nigh  in- 
j       credible,  not  merely  because  Thompson  is  a  good  authority, 
/^       but  because  in  all  its  essential  details  it  has  been  uncoi.- 
sciously  corroborated  by  the  observations  of  a  friend  of  my 
own,  VIZ.,  the  late  Dr.  W.  Bryden,  C.B.    This  gentleman, 
without  being  cognizant  of  the  above  anecdote,  told  me  that 
he  had  himself  repeatedly  witnessed  a  tame  monkey  (I  forget 
the  species)  in  India  lying  on  its  back  perfectly  motionless 
for  long  periods  of  time,  till  the  crows  in  the  neighbourhood, 
supposing  him  to  be  dead,  approached  within  grasping  dis- 
tance, when  he  used  to  make  a  sudden  spring  at  one  of  them, 
and  proceed  slowly  to  pluck  it  alive,  apparently  for  the  mere 
love  of  gratifying  his  passion  of  cruelty— although,  however, 
he  used  to  suck  the  juicy  ends  of  the  larger  feathers.  As  I  can 
quite  rely  on  Dr.  Bryden's  veracity  and  cannot  imagine  how 
in  such  a  case  there  can  have  been  any  room  for  malobserva- 
tion,  I  am  inclined  to  lend  a  credence  to  the  above  anecdote 
which  I  should  otherwise  have  regarded  with  distrust. 

Now  if,  as  I  can  scarcely  doubt  from  Dr.  Bryden's  account, 
some  monkeys  display  the  remarkable  trick  of  really  and  of 
set  purpose  shamming  death,  the  only  possible  explanation  of 
the  fact  is  that,  having  observed  crows  to  congregate  round 
motionless  carcasses,  they  infer  that  by  remaining  motion- 


FEIGNING  DEATH. 


313 


less  they  may  induce  these  animals  to  come  within  grasping 
distance.  No  doubt  this  displays  an  astonishing  amount  o1 
deliberative  inference ;  but  it  is  to  be  observed  that  the  fact, 
if  It  is  a  fact,  does  not  imply  any  abstract  idea  of  death ;  it 
implies  only  the  idea  of  imitating  a  previously  observed 
quiescence  with  the  purpose  of  bringing  about  the  same 
result — approach  of  birds— which  that  quiescence  had  pre- 
viously been  observed  to  produce.  Seeing  that  monkeys  are 
highly  imitative  as  well  as  highly  observant  animals,  this 
interpretation  is  not  so  antecedently  incredible  as  at  first 
sight  it  no  doubt  appears. 

But  now  it  follows  that  if  monkeys  are  able  consciously 
and  with  deliberate  intent  to  remain  motionless  for  the  purpose 
of  gaining  a  particular  object,  other  and  almost  as  intelligent 
animals  may  do  the  same.  Thus,  notwithstanding  the  proba- 
bility previously  pointed  out  that  the  shamming  dead  of 
wolves  and  foxes  may  be  due  to  kataplexy,  there  here  arises 
a  possibility  of  its  being  due  to  intelligent  purpose.  As 
bearing  on  this  possibility,  I  will  quote  two  cases  which 
appear  to  have  been  sufficiently  well  observed. 

The  first  is  one  which  has  been  recently  published  by 
Brigade  Surgeon  G.  Bidie  in  "Nature"  (vol.  xviii,  p.  244). 
He  says : — 

"  Some  years  ago,  while  living  in  Western  Mysore,  I 
occupied  a  house  surrounded  by  several  acres  of  fine  pasture 
land.  The  superior  grass  in  this  preserve  was  a  great  tempta- 
tion to  the  village  cattle,  and  whenever  the  gates  were  open 
trespass  was  common.  My  servants  did  their  best  to  drive 
off  intruders,  but  one  day  they  came  to  me  rather  troubled, 
stating  that  a  Brahmin-bull  which  they  had  beaten  had 
fallen  down  dead.  It  may  be  remarked  that  these  bulls  are 
sacred  and  privileged  animals— being  allowed  to  roam  at 
large  and  eat  whatever  they  may  fancy  in  the  open  shops  of 
the  bazaar-men.  On  hearing  that  the  trespasser  was  dead,  I 
immediately  went  to  view  the  body,  and  there  sure  enough  it 
was  lying  exactly  as  if  life  were  extinct.  Being  rather  vexed 
about  the  occurrence  in  case  of  getting  into  trouble  with  the 
natives,  I  did  not  stay  to  make  any  minute  examination,  but 
at  once  returned  to  the  house  with  the  view  of  reporting  the 
afifair  to  the  district  authorities.  I  had  only  just  gone  for  a 
short  time  when  a  man,  with  joy  in  his  face,  came  running 
to  tell  me  that  the  bull  was  on  his  legs  again  and  quietly 


/ 
L 


If-! 


1  . 


i  um 


'  i    i    r     ■  :  ' 

314 


MENTAL  EVOLUTION  IN  ANIMALS. 


1     .'I 


!h 


I! 


Ml 


1 


grazing.  Suffice  it  to  say  that  the  brute  had  acquired  the 
trick  of  feigning  death  which  practically  rendered  its  expul- 
sion impossible,  when  it  found  itself  in  a  desirable  situation 
which  it  did  not  wish  to  quit.  The  ruse  was  practised  fre- 
quently with  the  object  of  enjoying  my  excellent  grass,  and 
although  for  a  time  amusing,  it  at  length  became  troublesome, 
and  resolving  to  get  rid  of  it  the  sooner,  I  one  day,  when  he 
had  fallen  down,  sent  to  the  kitchen  for  a  supply  of  hot 
cinders,  which  we  placed  on  his  rump.  At  first  he  did  not 
seem  to  mind  this  much,  but  as  the  application  waxed  hot, 
he  gradually  raised  his  head,  took  a  steady  look  at  the  site 
of  the  cinders,  and  finally  getting  on  his  legs  went  off  at  a 
racing  pace  and  cleared  the  fence  like  a  deer.  This  was  the 
last  occasion  on  which  we  were  favoured  with  a  visit  from 
Cur  friend." 

Now  here  we  have  a  case  of  apparent  simulation  of  death 
I  frequently  repeated  with  an  intelligent  purpose,  and  as  the 
/  narrator  is  a  medical  man,  we  mvst  suppose  that  the  simula- 
tion was  well  done.  Nevertheless,  the  idea  which  the 
animal  had  may  only  have  been  that  of  remaining  inert,  and 
trusting  to  his  weight  in  preventing  his  removal.  The  case, 
however,  is  unquestionably  a  remarkable  one,  and  the  inter- 
pretation which  I  have  suggested  becomes  perhaps  less  pro- 
bable in  view  of  the  other  case  to  which  I  have  alluded,  and 
which  I  shall  now  proceed  to  give.  This  case  is  published  in 
the  late  Mr.  Morgan's  book  on  the  Beaver  (p.  269),  and  he 
says  it  "  was  communicated  to  the  author  by  Mr.  Coral  C. 
White  of  Aurora,  New  York,  who  carried  out  the  fox.  His 
veracity  is  unimpeachable." 

"  A  fox  one  night  entered  the  hen-house  of  a  farmer,  and 
after  destroying  a  large  number  of  fowls,  gorged  himself  to 
such  repletion  that  he  could  not  pass  out  through  the  small 
aperture  by  which  he  had  entered.  The  proprietor  found 
him  in  the  morning  sprawled  out  upon  the  floor,  apparently 
dead  from  surfeit ;  and  taking  him  up  by  the  legs  carried  him 
out  unsuspectingly,  and  for  some  distance  to  the  side  of  his 
house,  where  he  dropped  him  upon  the  grass.  No  sooner  did 
Eeynard  find  himself  free  than  he  sprang  to  his  feet  and 
made  his  escape.  He  seemed  to  know  that  it  was  only  as  a 
dead  fox  that  he  would  be  allowed  to  leave  the  scene  of  his 
spoliations ;  and  yet  to  devise  this  plan  of  escape  required 
no  ordinary  effort  of  intelligence,"  &G. 


i      :l 


FEIGNING  DEATH. 


315 


If  the  facts  are  here  correctly  recorded  (and  in  aU  the 
points  upon  which  I  am  about  to  dweU  they  agree  closely 
with  some  of  the  cases  given  by  Couch),  one  would  scarcely 
suppose  that  the  mere  approach  of  a  man  in  openina  the 
door  of  the  hen-house  could  have  caused  either  the  kind  or 
degree  of  alarm  which  is  known  to  produce  kataplexy ;  while 
It  IS  somewhat  doubtful  whether  the  stimulus  occasioned  by 
dropping  the  fox  upon  the  grass  would  have  been  sufficient 
suddenly  to  dispel  the  kataplectic  state.     Therefore,  in  such  a 
case  as  this  it  seems  to  me  that  the  probability  rather  inclines 
to  the  shamming  dead  having  been  due  to  an  intelligent  pur- 
pose,  even  although  we  may  not  suppose  the  animal  to  have 
had  any  idea  either  of  death  as  such,  or  of  its  conscious 
simulation.    Thus  the  case  with  respect  to  the  higher  animals 
--It  we  have  due  regard  to  all  the  evidence  which  has  now 
been  presented— seems  to  me  one  of  no  small  difficulty    The 
truth  simply  is  that  there  is  a  lack  of  sufficient  observation 
by  experimental  means,  to  determine  whether  wolves  and 
more  especially  foxes,  simulate  death-i.g.,  remain  motion- 
less in  certain  circumstances  of  danger  with  the  conscious 
purpose  ol  iurthering  their  escape ;  or,  perhaps  almost  as 
probably,  whether  the  motionless  condition  of  these  animals 
under  such  circumstances  is  due  to  the  occurrence  of  the 
hypnotic  state.     With  regard  to  these  animals,  therefore,  as 
with  regard  to  the  Brahmin-buU,  I  have  thought  it  best  not 
to  express  a  definite  opinion  either  way;  but  rather  to  pre- 
sent all  the  evidence  on  both  sides  with  the  view  of  stimu- 
lating experimental  enquiry  of  the  kind  that  I  have  sug- 
gested by  any  one  who  may  have  the  opportunity  of  con- 
ducting  It.*     Such  an  enquiry  having  been  conducted   by 
Mr.  Darwin  in  the  case  of  insects  and  spiders  has  closed  the 
question  as  far  as  they  are  concerned,  by  leaving  no  room  to 
suppose  that  their  beha-iour  is  due  to  conscious  purpose. 
The  evidence  with  regard  to  the  higher  Mammalia,  on  the 
other  hand,  points   to  a  different  conclusion,  for  the  full 
establishment  of  which  further  and  corroborative  evidence  is 
doubtless  necessary. 

Be  it  observed,  however,  that  in  these  cases  the  difficulty 

.f-^nH  ll^"";^'  ^\^J^'^-  ''**^^  ^^^i"g  '•^'^•i  ^^^  aboTe  and  so  having  under- 
8tx>od  the  nature  of  the  question,  had  laid  down  his  fox  upon  the  grts  with 
extreme  gentleness  and  immediately  concealed  himself,  he  might  greatly  have 
furthered  the  solution  of  the  (iuestibn.  "     S**^""/  "ave 


^^aml 

1 

'I 

„  jlJu 

■:i-  ■  I  ^ 


u 


316 


MENTAL  EVOLUTION  IN  ANIMALS. 


has  no  reference  to  any  question  of  instinct — for,  unlike  the 
case  of  insects,  the  habit  is  much  too  exceptional  to  be 
regarded  as  instinctive — but  to  determining  whether  the 
facts  are  due  to  intelligent  purpose  or  to  some  purely  physio- 
logical effects  of  fear.  In  the  more  remarkable  of  the  above- 
quoted  cases,  no  doubt,  the  latter  hypothesis  is  not  available; 
but  it  may  be  so  in  some  of  the  others,  and  even  where  this 
hypothesis  is  not  available,  it  becomes  most  desirable  to 
understand  the  class  of  ideas  which  indur-  '\  faimtil  to 
behave  in  a  manner  so  closely  simulating  de.  *  'ere,  how- 
ever, I  am  only  concerned  with  showing  that  i  v  difficulty  of 
arriving  at  such  an  understanding  has  nothing  to  do  with  the 
present  theory  as  to  the  formation  of  instinct. 


I '. 


!!li 


•u 


jJii 


t       ■ 


Feigning  Injury, 

In  the  "  Contemporary  Eeview  "  (July  1875)  the  Diike 
of  Argyll,  in  an  article  on  "  Animal  Instinct,"  argues  that  the 
female  duck  could  hardly  have  consciously  learnt  to  imitate 
the  movements  of  a  wounded  bird ;  and  that  the  young  merg- 
ansers, which  squat  on  the  mud  when  alarmed  and  are  thus 
made  inconspicuous  while  the  old  ones  fly  away,  are  in  the 
same  case.  Mr.  Darwin,  in  some  MS  notes  on  this  article, 
observes  that  he  agrees  with  the  Duke  in  not  ascribing  the 
deceptive  movements  of  the  female  duck,  &c.,  to  conscious 
imitation  of  wounded  birds ;  but  thinks  that  a  female  bird 
which,  from  solicitude  for  her  nestlings,  would  endeavour  to 
fight  a  threatening  quadruped  as  a  hen  does  a  dog,  might, 
by  alternately  attacking  and  retreating,  inadvertently  draw 
the  enemy  away  from  the  nest.  Natural  selection,  acting  on 
this  primitive  habit,  might  then  develop  the  running  away 
from  the  nest  as  an  instinct ;  and  if,  as  is  probable,  carni- 
vorous quadrupeds  would  be  more  likely  to  follow  birds 
apparently  unable  to  fly  than  birds  apparently  well,  the 
action  of  drooping  the  wing,  &c.,  might  have  been  slowly 
developed. 

The  instinct  of  squatting  shown  by  young  birds,  which 
are  thus  rendered  inconspicuous,  was  no  doubt  acquired  in 
the  same  way  and  for  the  same  reason  as  the  instinct  of 
shamming  dead  in  insects.  The  instinct,  however,  in  the 
case  of  young  birds  may  have  originally  been  acquired  by 
older  animals   (due  in  the  first  instance  to  being  partlj 


FEIGNING  INJURY. 


317 


inlike  the 
lal  to  be 
ether  the 
\y  physio- 
ihe  above- 
available; 
vhere  this 
3irable  to 
f'aimtil  to 
'ere,  how- 
fficulty  of 
)  with  the 


bhe  Duke 
s  that  the 
;o  imitate 
ing  merg- 
1  are  thus 
ire  in  the 
is  article, 
ribing  the 
conscious 
male  bird 
eavour  to 
og,  might, 
itly  draw 
acting  on 
ing  away 
)le,  carni- 
iow  birds 
well,  the 
en  slowly 

ds,  which 
jquired  in 
iistinct  of 
sr,  in  the 
q[uired  by 
Qg   partl;^ 


paralyzed  by  fright),  and  then,  in  ancordance  with  the  general 
principles  of  heredity,  being  inherited  at  an  earlier  age  by  the 
progeny. 

It  will  thus  be  seen  that  Mr.  Darwin  was  disposed  to 
attribute  the  instinct,  both  of  the  mother  and  young  to  an 
exclusively  primary  origin ;  but  I  confess  that  the  case  does 
appear  to  my  mmd  one  of  difficulty,  and  I  am  rather  inclined 
to  think  that  the  instinct  of  the  mother  in  the  case  of  the 
duck,  peeweet,  partridge,  and  all  birds  which  present  it, 
must  have  originally  been  assisted  by  intelligence.  It 
must  be  admitted,  from  what  we  know  of  hens,  that  the 
maternal  feelings  may  be  so  strong  as  to  lead  to  a  readi- 
ness to  incur  danger  or  death  rather  than  that  the  brood 
should  do  so.  Tlierefore,  when  in  the  presence  of  a  four- 
footed  enemy  the  mother  bird  begins  alternately  attack- 
ing and  retreating  in  the  manner  alluded  to  by  Mr.  Darwin, 
if  she  were  intelligent  enough  to  observe  that  on  retreating 
without  taking  wing  she  was  followed  up,  there  can  be  no 
doubt  that  she  might  with  intentional  purpose  thus  lure 
away  the  enemy  from  her  young.  If  so,  those  parents  which 
had  sense  enough  to  adopt  this  device  would  no  doubt  be 
able  to  rear  a  greater  number  of  broods  than  could  the  less 
observant  parents  ;  and  the  young  broods  of  such  intelligent 
parents  would  inherit  a  tendency  to  adopt  this  device  when 
they  themselves  became  mothers.  Thus  the  originally  intel- 
ligent device  would  slowly  become  organized  into  an  instinct, 
and  so  be  now  performed  with  mechanical  promptitude  by 
every  individual  partridge,  plover,  and  duck.  The  greatest 
dithculty  13  to  account  for  the  drooping  of  the  wing,  and  this, 
I  think,  can  only  be  done  by  regarding  it,  with  Mr.  Darwin^ 
as  of  an  unblended  primar-  origin.  The  case,  however  is 
unquestionably  very  remarkaule. 

Such  are  the  only  instincts  which  have  occurred  to  me  as 
hkely  to  present  any  special  difficulty  to  the  foregoing  theory 
of  the  origin  and  development  of  instincts  in  general.  Mr. 
Darwm  m  his  chapter  on  Instinct  in  the  "  Origin  of  Species  " 
has  fully  discussed  several  other  instincts  in  this  connection 
(viz.,  the  parasitic  instinct  of  the  cuckoo,  the  cell-makincr 
instinct  of  bees,  and  the  slave-making  instinct  of  ants);  but 
as  these  do  not  present  any  real  difficulty,  I  shall  not  wait 
to  go  over  the  ground  already  so  thoroughly  traversed  by 

21 


318 


MENTAL  EVOLUTION  IN  ANIMALS. 


CHAPTER  XIX. 


Eeason. 


i  '  Ml 


!   ' 


11 


I  SHALL  begin  this  chapter  by  quoting  from  "  Animal  Intel- 
ligence my  definition  of  the  word  "  Reason,"  in  order  that 
my  use  of  the  word  may  be  clearly  understood. 

^  "Reason  is  the  faculty  which  is  concerned  in  the  inten- 
tional adaptation  of  means  to  ends.  It  therefore  implies  the 
conscious  knowledge  of  the  relation  between  means  employed 
and  ends  attained,  and  may  be  exercised  in  adaptation  to 
circumstances  novel  alike  to  the  experience  of  the  individual 
and  to  that  of  the  species."  In  other  words,  "  it  implies  the 
power  of  perceiving  analogies  or  ratios,  and  is  in  this  sense 
equivalent  to  the  term  'ratiocination,'  or  the  faculty  of 
dexiucing  inferences  from  a  perceived  equivalency  of  relations 
This  latter  is  the  only  use  of  the  word  that  is  strictly  legiti- 
mate, and  it  IS  thus  that  I  shall  use  it  throughout  the  present 
treatise.  This  faculty,  however,  of  balancing  relations  draw- 
ing inferences,  and  so  of  forecasting  probabilities,  admits  of 
numberless  degrees." 

The  object  of  the  present  chapter  will  be  that  of  tracin^r 
the  probable  genesis  of  this  faculty,  and,  in  order  to  crive 
clearness  to  the  discussion,  I  desire  it  to  be  remembered  that 
I  reserve  the  terms  Reason  and  Ratiocination  to  designate 
the  faculty  above  defined.  I  shall  use  the  term  Inference  to 
designate  the  less  highly  developed  mental  antecedents  out 
ot  which,  as  I  shall  show,  I  conceive  Reason  to  have  been 
evolved.  No  doubt  every  act  of  reason  is  also  an  act  of  in- 
ference, but  we  shall  find  that  it  is  absolutely  necessary  to 
have  some  word  to  signify  indifferently  the  lowest  and  the 
highest  stages  of  that  whole  class  of  mental  processes  which 
culminates  m  symbolic  calculation.    The  word  Inference  is 


fit 


m 


REASON. 


319 


the  best  that  I  can  find,  and  therefore  it  will  bo  understood 
that  in  my  usage,  while  all  acts  of  reason  are  likewise  acts  of 
inference,  all  acts  of  inference  need  not  be  acts  of  reason. 

Thus  much  as  to  terminology  being  premised,  I  may  pass 
to  the  subject  of  the  present  chapter.  I  have  already,  in 
earlier  chapters,  endeavoured  to  show  how  it  is  probable  that 
consciousness  arises  out  of  reflex  action  (or  that  the  mind- 
element  becomes  attached  to  nervous  processes  of  adjustment), 
when  the  latter  arrives  at  such  a  degree  of  complexity,  or  has 
reference  to  external  circumstances  having  such  a  degree  of 
inconstancy,  that  the  nerve-centre  becomes  a  seat  of  com- 
parative turmoil  among  molecular  forces.  Whenever  this 
stage  is  reached,  and  a  nerve-centre  begins  to  become  con- 
scious of  its  own  working,  we  pass,  according  to  my  classifi- 
cation, from  the  domain  of  reflex  action  into  that  of  instinct 
—instinct  being,  in  my  terminology,  reflex  action  into  which 
there  is  imported  the  element  of  consciousness.  But  now,  as 
during  the  course  of  evolution  the  lower  forms  of  life  are 
required  progressively  to  adjust  their  actions  to  circum- 
stances of  growing  complexity  and  inconstancy,  or  to  occasions 
of  growing  infrequency,  it  follows  that  the  organized  instincts 
with  which  they  are  endowed  must  at  some  point  begin  to 
become  inadequate;  a  greater  flexibility  in  the  power  of 
adjustive  response  is  needed,  and  if  any  such  flexibility  is 
possible  under  the  conditions  of  ganglionic  action,  those 
individuals  which  best  attain  to  it  will  survive,  and  so  the 
improvement  will  become  general  to  the  species.  Now  we 
know  tha,t  such  an  increase  of  flexibility  is  possible  under 
the  conditions  of  ganglionic  action,  and  this  increase  of 
flexibility  on  its  subjective  side  we  know  as  the  faculty  of 
reason.  It  is  here  needful  to  consider  in  what  this  faculty 
consists. 

While  treating  of  the  genesis  of  Perception  I  pointed  out 
that  the  faculty  admits  of  numberless  degrees  of  elaboration. 
These  we  found  to  depend  largely,  or  even  chiefly,  upon  the 
degree  of  complexity  presented  by  the  objects  or  relations 
perceived.  Now  when  a  perception  reaches  a  certain  degree 
of  elaboration,  so  that  it  is  able  to  take  cognizance  of  the 
relation  between  relations,  it  begins  to  pass  into  reason,  or 
ratiocination.  Contrariwise,  in  its  highest  stages  of  develop- 
ment, ratiocination  is  merely  a  highly  complex  process  of 
perception— ie.,  a  perception  of  the  equivalency  of  perceived 


^■'1 


f' 


I 


mMU^ 


i. 


<  I     t 


^^   !     f'i 


t. " 


/r? 


i* 


320 


MENTAL  EVOLUTION  IN  ANIMALS. 


ratios  which  are  themselves  more  or  loss  elaborated  percepts 
formed  out  of  simpler  percepts,  or  percepts  lying  nearer  to  the 
immediate  data  of  sensation.     Thus,  universally  ratiocination 
may  be  considered  as  the  higher  development  of  perception ; 
for  at  no  point  can  we  draw  the  line  and  say  that  the  two  are 
distinct.     In  other  words,  a  perception  is  always  in  its  essen- 
tial nature  what  logicians  term  a  conchision,  whether  it  has 
reference  to  tlie  simplest  memory  of  a  past  sensation  or  to  the 
highest  product  of  abstract  thought.     For  when  the  highest 
product  of  abstract  thought  is  analyzed,  the  ultimate  elements 
must  always  be  found  to  consist  in  material  given  directly  by 
the  senses ;  and  every  stage  in  the  symbolic  construction  of 
ideas  in  which  the  process  of  abstraction  consists,  depends 
upon  acts  of  perception  taking  place  in  the  lower  stages. 
True  it  is  that  these  acts  of  perception  here  have  reference  to 
the  symbols  of  ideas,  which  may  themselves  be  far  removed 
from  the  simple  and  immediate  memories  of  past  sensations ; 
but  as  we  can  nowhere  draw  the  line  between  perception  of 
the  one  order  and  perception  of  the  other,  we  ought  to  reco"- 
nize  that  in  the  case  of  this  faculty  there  is  nowhere  any 
difference  in  kind,  although  everywhere  a  difference  in  degree : 
or,  otherwise  stated,  intellectual  processes  which  culminate  iii 
symbolic  reasoning  are  everywhere  processes  of  cognition, 
and  of  these  processes  the  term  perception  is  a  generic  name.  ' 
But  having  thus  shown  that  in  my  opinion  there  is  no 
real  break  between  cognition  of  the  lowest  and  of  the  highest 
order,  I  must  next  show  at  what  places  I  think  it  is  conve- 
nient, for  the  sake  of  historical  description,  to  mark  off  what 
I  may  term  conventional  stages  in  the  development  of  cog- 
nition.   This  I  have  already  done  for  the  lower  stages  of  such 
development  in  my  chapter  on   Perception,  where  it  was 
shown  that  the  first  stage  consists  in  merely  perceiving  an 
ev<-,ernal  object  as  an  external  object,  the  next  stage  in  rQco<y- 
nizing  the  simplest  qualities  of  an  object,  the  third  sta^e  m 
mentally  grouping  objects  with  reference  to  their  perceived 
qualities  or  relations,  and  the  fourth  stage  in  inferring  un- 
perceived  qualities  or  relations  from  perceived  ones— as  when 
on  hearing  a  growl  I  immediately  infer, the  presence  of  a 
dangerous  dog, 

Now  from  this  it  is  apparent  that  the  process  of  Inference, 
with  which  we  are  in  this  chapter  concerned,  is  never  in  its' 
earlier  or  least  developed,  stages  a  process  of  conscious  com- 


EEASON. 


821 


stages. 


no 


was 


parison.  Tlie  inference  is  formed  out  of  the  perception,  as  it 
were,  immediately,  and  does  not  require  to  pass  thiou"h  any 
such  process  of  reflection  as  the  term  ratiocination  is  apt  and 
indeed  ought,  to  imply ;  the  ratios  at  this  stage  are  perceived 
compared,  and  the  inference  from  them  drawn,  without  the 
need  of  deliberate  thought.  For  instance,  I  am  hurrying  to 
catch  a  train,  and  meet  a  man  in  the  street  hurrying  in°the 
opposite  direction ;  we  both  begin  rapidly  to  dance  from  side 
to  side  m  our  endeavour  to  pass  one  another,  and  each  time 
we  do  so  It  13  evident  that  we  have  each  inferred  that  the 
other  will  pass  on  the  opposite  side :  yet  these  successive  acts 
ot  inference  are  made  with  such  rapidity,  that  not  only  has 
there  been  no  deliberate  thought  in  the  matter,  but  it  is  only 
by  such  thought  that  I  can  afterwards  find  that  I  must  have 
performed  so  many  separate  acts  of  inference. 

Clearly,  then,  it  is  in  these  lower  stages  of  perception 
that  we  have  to  look  for  the  lirst  germ  of  reason :  for  this 
purpose,  let  us  first  interrogate  our  own  perceptions.    The 
large  measure  in  which  inference  enters  into  the  very  struc- 
ture even  of  our  most  habitual  perceptions  is  easily  shown 
Sir  David  Brewster  has  noticed  the  fact,  which  must  have 
been  observed  by  every  one,  that  when  looking  through  a 
window  on  the  pane  of  which  there  is  a  fly  or  a  gnat,  if  the 
eyes  are  adjusted  for  a  greater  distance,  so  that  the  gnat  is 
not  clearly  focussed,  the  mind  at  once  infers  that  it  is  a  bird, 
or  some  other  much  larger  object  seen  at  a  greater  distance.* 
Now  this  shows  that  in  the  case  of  all  our  visual  perceptions 
mental  inference  is  perpetually  at  work,  compensating  for  the 
effects  of  distance  in  diminishing  apparent  size.     No  less 
constant  muse  be  the  work  of  mental  inference  in  compen- 
sating for  the  effects  of  the  "blind  spot"  upon  the  retina. 
For  if  the  vision  be  directed  to  a  coloured  surface,  the  part  of 
the  surface  which,  on  account  of  the  blind  spot,  is  not  really 
seen,  yet  appears  to  be  seen ;  and  not  only  so,  but  it  appears 
to  be  coloured  the  same  tint  as  the  rest  of  the  surface,  what- 
ever this  may  happen  to  be :  unconscious  inference  supplies 
the  colour.     Mr.  Sully  has  devoted  a  large  part  of  his  work 
on  "  Illusions"  to  a  survey  and  classification  of  "  The  Illusions 
of  Perception ;"  and  in  most  of  the  instances  which  he  gives 
It  is  apparent,  as  he  observes,  that  the  illusion  arises  through 
the  mental  "  application  of  a  rule,  valid  for  the  majority  of 

•  Letters  on  Natural  Magic,  VII. 


I 


322 


j; 


')'  'i    , 


',!■ 


MENTAL  EVOLUTION  IN  ANIMALS. 


cases,  to  an  oxceptional  case" — i.e.,  the  illusion  arises  from  an 
erroneous  infercmce.  It  therefore  seems  needless  for  me  to 
occupy  space  with  an  enumeration  of  instances. 

The  first  or  earliest  stage  of  inference,  then,  is  that  in 
which  the  inference  arises  in  or  together  loith  the  perception, 
as  when  we  infer  that  a  gnat  is  a  bird,  or  that  the  portion  of 
a  surface  corresponding  to  the  blind  spot  of  the  retina  is 
coloured  like  the  surrounding  portions  of  the  surface ;  infe- 
rence may  here  be  said  to  bo  a  constituent  part  of  perception.* 
In  other  words,  wo  do  not  in  such  cases  really  scnsate  all  that 
we  perceive,  and  the  residue  of  the  perception  is  supplied  by 
inference  which  is  unconscious  only  because  it  is  so  instan- 
taneous. Tiie  reason  why  in  such  cases  it  is  so  instantaneous, 
is  because  the  part  furnished  by  inference  has  been  so 
habitually  associated  with  the  part  furnished  by  sensation, 
that  the  instant  the  sensation  is  perceived  the  mental  addition 
is  supplied.  That  this  is  the  true  explanation  of  the  matter 
is  rendered  evident,  not  only  from  the  deductive  considera- 
tions just  stated,  but  also  from  the  inductive  verification 
which  they  receive  from  the  facts  that  arise  when  a  man  who 
has  been  born  blind  is  suddenly  made  to  see,  A  good  case  of 
this  kind  is  the  celebrated  one  of  the  youth  (about  twelve  years 
of  age)  whom  Mr,  Cheselden  couched  for  removing  congenital 
cataracts  from  both  eyes.  I  shall  therefore  quote  a  few  pas- 
sages from  Mr.  Cheselden's  account  of  the  case. 

"  When  he  first  saw  he  was  so  far  from  making  any  judg- 
ment about  distances,  that  he  thought  all  objects  whatever 
touched  his  eyes  (as  he  expressed)  as  what  he  felt  touched 
his  skin,  and  thought  no  objects  so  agreeable  as  those  which 
were  smooth  and  regular,  though  he  could  form  no  judgment 
of  their  shape,  or  guess  what  it  was  in  any  object  that  was 
pleasing  to  him.  He  knew  not  the  shape  of  anything,  nor 
any  one  thing  from  another,  however  different  in'  dhape  and 
magnitude;  but  upon  being  told  what  things  were,  whose 
form  he  before  knew  from  feeling,  he  would  carefully  observe, 
that  he  might  know  them  again;  but  having  too  many 
objects  to  learn  at  once,  he  forgot  many  of  them ;  and  (as  he 
said)  at  first  learnt  to  know,  and  again  forgot  a  thousand 
things  in  a  day.  One  particular  only  (though  it  may  appear 
trifling)  I  will  relate.    Having  often  forgotten  which  was  the 

*  Just  in  the  same  way  as  wo  found  perception  to  form  an  integral  part 
of  MemoT/  and  of  the  Asaociatioa  of  Ideaa. 


REASON. 


323 


fl 


cat  and  which  was  the  dog,  he  was  ashamed  to  ask;  but 
catching  the  cat  (wliich  he  knew  by  feeling)  he  was  observed 
to  look  at  her  steadfastly,  and  then  setting  her  down  said, 
'  So  puss  !  I  shall  know  you  another  time.'  .  .  .  Wo  thought 
he  soon  knew  what  pictures  were  which  were  showed  to  him, 
but  we  found  afterwards  we  were  mistaken ;  for  about  two 
months  after  he  was  couched,  he  discovered  at  once  they 
represented  solid  bodies,  wlien  to  that  time  he  considered 
them  as  only  party-coloured  planes,  or  surfaces  diversified 
with  variety  of  paints ;  but  even  then  he  was  no  less  sur- 
prised, expecting  the  pictures  would  feel  like  the  things  they 
represented;  and  was  amazed  when  he  found  those  parts, 
which  by  their  light  and  shadow  ap])eaied  round  and  uneven, 
felt  only  flat  like  the  rest ;  and  asked  which  was  the  lying 
sense,  feeling  or  seeing." 

Dr.  W.  B.  Carpenter  gives  a  somewhat  similar  case  which 
fell  within  his  own  observation;*  but  taking  the  above  as 
sufficient  for  our  purposes,  it  is  evident  that  the  youth,  upon 
being  first  able  to  see,  was  not  able  to  supply  any  of  those 
mental  inferences  from  his  visual  perceptions  which  alone 
could  make  these  sensations  of  any  practical  use  as  guides  or 
stimuli  to  action :  that  is  to  say,  in  the  absence  of  these 
inferences,  these  perceptions  were  imperfect.  But  he  imme- 
diately set  about  establishing  consciously,  or  with  deliberate 
intention,  those  numberless  associations  between  sight  and 
touch  which  are  usually  ac'iuired  in  early  infancy,  and  which 
are  required  to  constitute  the  data  of  the  mental  inferences 
which  we  are  considering.  The  number  of  such  special  asso- 
ciations required  being  so  great  and  varied,  we  may  wonder 
that  even  within  the  space  of  three  months  he  should  have 
been  able  to  have  made  so  much  progress  as  to  feel  his  visual 
perception  deceived  by  the  arts  of  shading  and  perspective ; 
but  on  this  point  I  shall  have  more  to  say  presently.  Mean- 
while it  is  enough  to  remember  that  the  case  proves  the 
utility  of  all  our  visual  perceptions  to  depend  upon  the  ingre- 
dient of  mental  inference  which  is  supplied  by  habitual 
association ;  and,  of  course,  we  cannot  doubt  that  the  same  is 
true  of  perceptions  yielded  by  the  other  senses.f 

•  Human  Physiology,  7th  ed.,  p.  103,  and  in  more  detail,  Contemp.  Sev^ 
»ol.  xxi,  pp.  781  -2. 

t  As  Adam  Smith  observes,  in  his  comments  upon  this  case,  "  When  the 
young  gentleman  said  that  objects  which  he  saw  touched  his  ejes,  he  cer- 


I 


! 


il 


Mill 


ft      V 


324 


MENTAL  EVOLUTION  IN  ANIMALS. 


.■I     '! 


'.if!''  *  .  , 


Such,  then,  I  conceive  to  be  the  first  or  most  rudimentary 
stage  of  inference,  where,  in  virtue  of  constant  association, 
the  act  is  organically  bound  up  with  a  sensuous  perception, 
so  as  in  fact  to  constitute  an  integral  part  of  such  perception, 
and  therefore  to  be  precluded  from  ever  emerging  into  con- 
sciousness as  a  separate  act  of  mind.  The  next  stage  in  the 
process  of  inference  I  take  to  be  the  one  which  Mr.  Spencer 
regards  as  the  earliest  stage.  This,  in  his  words,  is  "that 
reasoning  through  which  the  great  mass  of  surrounding  co- 
existences and  sequences  are  known."*  That  is  to  say,  when 
habitually  co-existing  groups  of  external  objects,  attributes, 
and  relations  recognized  become  too  numerous  and  too  com- 
plex to  be  all  recognized  simultaneously,  or  when  the  first  in 
a  series  of  habitually  successive  groups  occurs,  the  unper- 
ceived  objects,  attributes,  or  relations  are  inferred.  For 
instance,  if  a  sportsman  while  shooting  woodcock  in  cover 
sees  a  bird  about  the  size  and  colour  of  a  woodcock  get  up 
and  fly  through  the  foliage,  not  having  time  to  see  more  than 
that  it  is  a  bird  of  such  a  size  and  colour,  he  immediately 
supplies  by  inference  the  other  qualities  of  a  woodcock,  and 
is  afterwards  disgusted  to  find  that  he  has  shot  a  thrush.  I 
have  done  so  myself,  and  could  hardly  believe  that  the  thrush 
was  the  bird  I  had  fired  at,  so  complete  was  my  mental  sup- 
plement to  my  visual  perception.  And,  without  waiting  to 
give  illustrations,  it  is  evident  that  the  same  principles  apply 
to  the  case  of  habitual  sequences. 

The  second  stage  of  inference,  then,  is  reached  when, 
owing  to  a  constant  association  of  objects,  qualities,  or  rela- 
tions in  the  environment,  a  correspondingly  constant  associa- 
tion of  ideas  is  produced  in  the  mind,  such  that  when  some 
members  of  the  external  group  are  perceived,  the  other 
members  of  it  are  inferred.  Inference  at  this  stage  resembles 
inference  at  the  earlier  stage  which  we  have  considered  in 
one  respect,  and  differs  from  it  in  another.  The  resemblance 
consists  in  the  act  of  inference  being  too  rapid  to  admit  of  its 

tainly  could  not  mean  that  they  pressed  upon  or  resisted  his  eyes  .  .  .  , 
He  oould  Tnean  no  more  than  that  they  were  close  upon  his  eyes,  or  to  speak 
more  properly,  perhaps,  that  they  were  in  his  eyes.  A  deaf  man,  who  was 
made  all  at  once  to  hear,  might  in  the  same  manner  naturally  enough  say, 
that  the  sounds  which  he  heard  touched  his  ears,  meaning  that  he  felt  them 
as  close  upon  his  ears,  or,  to  speak  perhaps  more  properly,  as  in  his  eon." 
{Essay  on  External  Senses.)  , 

*  .Principles  of  Psychology,  vol.  i,  p.  458. 


REASON. 


325 


being  consciously  recognized  as  an  act  of  mind  separate  or 
distinct  from  the  perception.  The  difference  consists  in  sub- 
sequent reflection  being  able  to  show  that  the  act  of  inference 
was  distinct  from  the  act  of  perception,  and  rmtst  have  been 
separated  from  it  by  a  short  interval  of  time  ;  the  inference 
did  not,  as  in  the  previous  cases,  constitute  an  integral  part 
of  the  perception. 

The  next  stage  which  we  are  able  to  distinguish  in  tho 
faculty  of  inference  is,  I  think,  that  of  the  conscious  com- 
parison of  objects,  qualities,  or  relations.  Here  we  arrive  at 
ratiocination  strictly  so  called ;  but  still  not  necessarily  at 
self-conscious  thought.  At  this  stage  we  make  what  Mr. 
Mivart  calls  "  practical  inferences ;"  that  is  to  say,  we  com- 
pare one  group  of  ratios  with  another,  but  without  thinking 
of  them  as  ratios.  Thus,  for  instance,  if  I  meet  a  cut- throat 
looking  man  upon  a  lonely  road  in  Ireland,  I  may  begin  con- 
sciously to  determine  the  probabilities  whether  he  is  one  of  a 
"  brotherhood,"  and  if  so  whether  he  is  waiting  for  me ;  but 
I  cast  the  matter  over  in  my  mind  while  we  are  approaching 
one  another,  without  waiting  to  think  about  my  thoughts.  If 
I  do  wait  to  think  about  them,  I  know  that  I  have  been 
carrying  on  a  process  of  reasoning ;  but  I  have  equally  carried 
on  that  process  whether  or  not  I  ever  think  about  it  after- 
wards as  a  process. 

The  last  or  highest  stage  of  reasoning  is  attained  when 
the  process  admits  of  being  consciously  recognized  as  a  pro- 
cess, or  itself  becomes  an  object  of  knowledge.  This  is  the 
stage  at  which  it  first  becomes  possible  intentionally  to 
abstract  qualities  or  relations  for  the  purposes  of  inference. 
Here,  therefore,  it  first  becomes  possible  to  use  symbols  of 
ideas  instead  of  the  actual  ideas  themselves,  and  so  it  is  here 
that  the  "Logic  of  Signs  "  first  emerges  from  the  "Logic  of 
Feelings."  In  my  next  work  I  shall  have  a  great  deal  to  say 
touching  this  final  stage ;  but  as  it  only  occurs  in  Man,  I  have 
nothing  more  to  say  about  it  at  present. 

Turning  now  to  animals,  it  is  evident  that  they  must 
present  the  first,  or,  as  we  may  call  it,  the  perceptive  stage  of 
inference  ;  for  otherwise  their  whole  mechanism  of  perception 
would  need  to  be  supposed  different  from  our  own.  But  there 
is  only  one  respect  in  which  this  mechanism  can  be  shown 
to  be  different,  and  this  consists  in  the  fact  already  mentioned 
in    former    chapters — viz.,    that  newly-hatched  birds  and 


0     im 


■i  r 


(I      :  ■ 


M  ! 


tm  M 


1 J  "  ^^^' 


H 


Slit. 


!ltl|i' 


826 


MENTAL  EVOLUTION  OP  ANIMALS. 


newly-born  mammals  are  able,  without  such  individual  ex- 
perience as  is  required  in  the  case  of  man,  immediately  and 
correctly  to  supply  all  the  mental  inferences  which  are 
needed  to  complete  their  sensuous  perceptions.  Of  course 
the  explanation  of  this  must  be  that  heredity  in  these  cases 
has  already  done  the  work,  so  that  the  young  animal  comes 
into  the  world  with  its  mental  endowments  of  perceptive 
inference  as  fully  elaborated  and  as  completely  efficient  as  its 
bodily  endowments  of  perceptive  sensations.  But  the  ques- 
tion arises,  Why  is  not  this  also  the  case  with  Man  ?  That 
it  is  not  the  case  is  sufficiently  proved  by  the  results  of 
couching  for  cataract  previously  quoted ;  but  why  it  should 
not  be  the  case  is  not  quite  so  clear,  and  hitherto  has  not  been 
sufficiently  considered ;  for  it  is  only  since  the  experiments  of 
Mr.  Spalding  that  the  facts  with  regard  to  animals  have 
become  known.*  I  think  the  answer  to  this  question  is 
as  follows. 

First  of  all,  there  is  no  evidence  to  show  that  even  in  the 
case  of  man  heredity  has  aot  played  a  very  important  part 
(though  not  so  important  as  with  animals)  in  supplying  the 
machinery  of  perceptive  inference.  Indeed  I  think  we  have 
some  evidence  to  show  that  it  has ;  for  only  by  supposing 
this  are  we  able  to  explain  why  the  youth  whose  case  was  so 
well  described  by  Mr.  Cheselden  was  able,  after  so  short  an 
interval  as  three  months,  to  perceive  the  illusory  effects  of 
shading  and  perspective  in  a  picture.  But,  even  if  it  be 
allowed  that  heredity  here  played  an  important  part,  there  is 
still,  no  doubt,  a  great  discrepancy  to  be  explained  in  the 
degree  of  its  influence  as  compared  with  its  absolute  per- 
fection in  the  case  of  the  lower  animals.  But  I  think 
there  are  two  considerations  which,  taken  together,  are  suffi- 
cient to  explain  the  discrepancy.  In  the  first  place  we  have 
already  seen,  when  treating  of  the  hereditary  instinctive 
endowments  of  animals,  that  the  machinery  of  these  endow- 
ments is  apt  to  be  thrown  out  of  gear  if  they  are  not  allowed 
full  play  at  the  time  of  life  when  they  ought  normally  to 
have  first  come  into  operation.  Therefore  in  the  case  of  this 
youth  it  seems  highly  probable  that  during  the  twelve  years 

*  Or  rather,  I  should  say,  so  well  known.  Houzeau  had  pointed  out 
that  while  young  infants  are  unable  to  localize  a  pain  or  other  sensation, 
newly -bom  calves  are  able  to  do  bo  with  precision  (see  Fac.  Mem.  det 
Animaux,  torn,  i,  p.  b2). 


EEASON. 


327 


of  his  congenital  blindness,  whatever  hereditary  endowments 
he  may  have  had  in  the  way  of  forming  perceptive  inferences 
relating  to  sight,  were  largely  aborted  by  disuse,  if  not  also 
thrown  out  of  gear.  The  other  consideration  is  that,  during 
these  *welve  years  his  faculties  of  perceptive  inference  were 
not  lying  idle,  but  were  thrown  with  all  the  greater  strength 
into  his  perceptions  arising  from  touch  and  hearing.  It  is 
therefore  abundantly  probable  that,  even  upon  this  lowest 
plane  of  inference,  the  strong  organization  which  had  been 
formed  between  this  faculty  and  the  perceptions  of  touch 
and  hearing,  made  it  all  the  more  difficult  for  this  faculty  to 
form  a  new  organization  with  the  perceptions  of  sight. 
Further  than  this,  I  think  it  is  not  improbable  that  the 
human  mind,  in  being  so  habitually  concerned  with  processes 
of  inference  on  higher  planes,  would  not  be  so  ready  to  build 
up  by  unconscious  association  a  mechanism  of  perceptive  or 
automatic  inference,  as  would  the  less  highly  elaborated  mind 
of  an  animal  similarly  situated.  Still,  notwithstanding  these 
considerations,  I  feel  that  it  would  be  welt  worth  while  to  try 
the  experiment  of  keeping  an  animal  blindfolded  from  the 
time  of  its  birth  till  it  is  a  year  or  two  old,  and  then  to  see, 
when  the  blindfolding  was  removed,  whether  or  not  its  facul- 
ties of  perceptive  inference  resemble  those  of  a  similar 
animal  soon  after  its  birth. 

That  inference  of  what  I  have  called  the  second  stage  also 
occurs  in  animals  no  one  will  dispute,  although,  of  course, 
some  psychologists  may  object  to  my  calling  this  particular 
case  of  the  association  of  ideas  by  the  name  of  inference.  I 
have  already  said  in  the  chapter  which  deals  with  Memory 
and  the  Association  of  Ideas,  that  it  is  impossible  to  say 
which  are  really  the  lowest  animals  that  possess  these 
faculties ;  and  therefore  it  is  still  more  impossible  to  say 
where  in  the  animal  kingdom  inference  of  the  first  or  of  the 
second  stage  begins  :  we  can  only  say  that  wherever  there  is 
visual  or  other  sensuous  perception  which,  as  a  perception, 
requires  to  form  an  estimate  of  distance  or  other  simple  rela- 
tion not  immediately  given  by  sensation,  but  mentally 
deduced  from  sensation — there  v.-?  must  suppose  that  in- 
ference of  the  first  stage  obtains ;  and  that  wherever  there  is 
an  association  of  ideas,  such  that  the  occurrence  of  one 
perception  arouses  an  inferred  knowledge  of  a  complement  of 
that  perception,  or  an  inferred  anticipation  of  a  future  event 


i   I'-'il 


-  fj 


m 


1  t      i 


M    l| 


ll    . 


^28 


MENTAL  EVOLUTION  OF  ANIMALS. 


U 


/.' 


—•there  we  must  suppose  that  inference  of  the  second  staf^e 
obtains.  And,  although  we  are  not  able  to  draw  the  lines 
with  precision,  we  know  that  both  these  conditions  occur  low 
down  among  the  Invertebrata, 

The  next  stage  of  inference  is  the  highest  that  obtains 
among  animals.  This  is  the  stage  in  which  objects,  qualities, 
-;;  and  relations  are  deliberately  compared  with  the  intention  of 
/  perceiving  likenesses  and  unlikenesses  (analogies) ;  the  action 
which  follows  is  therefore  undertaken  with  a  knowledge,  or 
perception,  of  the  relation  between  the  means  employed  and 
the  ends  attained.  This,  as  I  have  before  said,  is  the  stage  of 
the  process  of  inference  at  which  the  term  Reason  or  Eatio- 
cmation  first  becomes  appropriate,  and  therefore  it  is  with 
reference  to  this  stage  that  I  first  use  the  word.  That  this 
stage  of  the  process  of  inference  is  reached  by  nearly  all  the 
warm-blooded  animals,  and  even  by  some  of  the  Invertebrata, 
no  one,  I  thmk,  can  possibly  question.  If,  however,  anv  one 
should  do  so,  I  must  refer  him  to  my  previous  work ;  foi  the 
instances  there  given  are  so  numerous  that  it  would  be  tedious 
here  to  reproduce  even  the  more  striking  among  them.*  To 
my  mind  the  most  remarkable  of  these  instances  are  those 
which  have  reference  to  the  Hymenoptera ;  for  although  the 
faculty  does  not  attain  to  so  high  a  level  of  development 
among  them  as  it  does  among  some  of  the  warm-blooded 
Vertebrata,  it  certainly  has  attained  to  much  more  than  a 

•  For  the  sake  at  once  of  giving  a  striking  example  of  reason  in  an 
animal  most  nearly  approaching  man,  and  of  supplementing  a  deficiency  in 
my  tormer  treatise,  I  shall  here  quote  a  passage  from  Dr.  Bastian's  work  on 
The  Brain  as  an  Organ  of  Mind  (p.  329).  "  In  regard  to  the  high  degree  of 
Intelligence  of  the  Orang,  we  have  the  following,  on  the  best  of  testimony, 
trom  Lieuret,  who  says  {Anat.  Comp.  du  Syst.  Nerv.,  tom.  i,  p.  540)  — 

" '  One  of  the  Orangs,  which  recently  died  at  the  Menagerie  of  the  Musee. 
was  accaistomed,  whsn  the  dinner-hour  had  come,  to  open  the  door  of  the 
room  where  he  took  his  meals  in  company  with  several  persons.  As  he  was 
not  sufficemtly  tall  to  reach  as  far  as  the  key  of  the  door,  he  hung  on  to  a 
rope,  balanced  himself,  and  after  a  few  oscillations  very  quickly  reached  the 
key.  His  keeper,  who  was  rather  worried  by  so  much  exactitude,  one  day 
took  occasion  to  make  three  knots  in  the  rope,  which,  having  thus  been  made 
too  short,  no  longer  permitted  the  Orang-outang  to  seize  the  key.  The 
animal,  after  an  ineffectual  attempt,  recognizing  the  nature  of  the  obstacle 
which  opposed  his  desire,  climbed  up  -he  rope,  placed  himself  above  the  knots 
and  untied  all  ihree,\n  the  presence  of  M.  Geoffroy  Saint-Hilaire,  who  related 
the  fact  to  me.  The  same  ape  wishing  to  open  a  door,  his  keeper  gave  him  a 
bunch  of  fifteen  keys ;  the  ape  tried  them  in  turn  till  he  had  found  the  one 
which  lie  wanted.  Another  time  a  bar  of  iron  was  put  into  his  hands,  and  h« 
made  use  of  it  as  a  lever," ' 


REASON. 


329 


proportional  development  in  them;  and  this  whether  we 
consider  their  position  in  the  zoological  scale,  or  the  general 
structure  of  their  psychology  as  compared  with  that  of  other 
animals — so  that  if  the  whole  structure  of  their  psychology 
were  correspondingly  advanced,  these  insects  would  deserve 
to  be  placed  on  a  psychological  level  with  Birds,  if  not  with 
some  of  the  more  intelligent  of  the  Mammalia.  But  looking 
to  their  psychology  as  a  whole,  I  think  that  its  status  may 
most  fairly  be  assigned  to  the  level  on  which  I  have  placed  it 
in  the  diagram.  However,  I  do  not  conceal  that  the  peculiar 
nature  of  ant  and  bee  intelligence  makes  it  most  difficult  to 
compare  with  the  intelligence  of  higher  animals. 

Another  special  difficulty  with  reference  to  reason  in 
animals  meets  us  in  the  case  of  the  Beaver.  For,  as  remarked 
in  "Animal  Intelligence,"  "on  the  one  hand  it  seems  in- 
credible that  the  beaver  should  attain  to  such  a  level  of 
abstract  thought  as  would  be  implied  by  his  forming  his 
various  structures  with  the  calculated  purpose  of  achieving 
the  ends  which  they  undoubtedly  subserve.  On  the  other 
hand,  as  we  have  seen,  it  seems  little  less  than  impossible 
that  the  formation  of  these  structures  can  be  due  to  instinct." 
The  structures  specially  alluded  to  in  this  connection  were 
the  beaver  canals,  and  my  information  concerning  them  was 
derived  exclusively  from  the  work  of  the  late  Mr.  Lewis  H. 
Morgan.  Since  the  publication  of  "  Animal  Intelligence," 
however,  I  am  informed  from  private  sources  that  the  intelli- 
gence of  the  beaver  has  been  greatly  over-estimated.  My 
correspondents  have  undoubtedly  seen  much  of  the  habits  of 
American  beavers ;  but  as  I  place  confidence  in  the  observa- 
tions of  Mr.  Morgan,  I  do  not  feet  entitled  to  allow  the 
counter-statements  of  my  correspondents  to  nullify  them. 
Still,  I  must  allow  such  counter-statements  to  carry  a  con- 
siderable degree  of  weight,  and  therefore  I  feel  that  at  present 
it  is  most  judicious  to  say  that,  pending  further  and  trust- 
worthy observations,  I  am  not  really  in  a  position  to  discuss 
the  quality  of  reason  as  it  occurs  in  this  animal.  On  this 
account  I  tihould  not  here  have  referred  to  the  subject  at  all, 
were  it  not  that  in  my  previous  work  I  promised  to  discuss  it 
in  the  present  one.  Finding,  however,  since  then,  that  the 
facts  do  not  appear  to  be  so  certain  as  I  supposed,  I  prefer, 
with  this  explanation,  to  allow  the  matter  drop. 


330 


MENTAL  EVOLUTION  IN  ANIMALS. 


ii.f 


Recurring  now  to  my  views  on  the  origin  and  develop- 
ment of  Reason,  it  will  have  been  noticed  that  they  differ 
materially  from  those  of  Mr.  Herbert  Spencer,  and,  therefore, 
looking  to  the  influence  which  he  justly  exerts  upon  all 
matters  relating  to  psychological  analysis,  I  feel  that  it  is 
desirable  to  enter  at  some  length  into  an  explanation  of  the 
ground  on  which  I  have  been  here  reluctantly  compelled  to 
disagree  with  him.  Possibly  the  divergence  between  us  may 
not  be  so  important  as  at  present  I  am  led  to  suppose ;  but  if 
it  should  hereafter  admit  of  being  shown  that  such  is  not  the 
case,  I  need  scarcely  say  that  the  fact  would  be  a  matter  of 
sincere  gratification  to  me. 

According  to  Mr.  Spencer,  Reason  arises  out  of  "  com- 
pound reflex  action "  or  "  Instinct,"  when  this  reaches  a 
certain  level  of  compounding  or  complexity.*  Now  I  have 
already  given  the  considerations  which  induce  me  to  differ 
from  Mr.  Spencer  in  regarding  Instinct  as  compound  reflex 
action,  and  therefore  it  is  only  in  a  general,  way  that  I  am 
able  to  agree  with  him  in  his  theory  of  the  origin  and  de- 
velopment of  Reason.  Nevertheless,  m  a  general  way  I  am 
able  to  agree  with  him,  and  therefore  I  shall  begin  by  statin^^ 
the  points  in  which  I  do  so.  " 

First  he  says :— "  The  impossibility  of  establishing  any 
line  of  demarkation  between  the  two  [Instinct  and  Reason] 
may  be  clearly  demonstrated.  If  every  instinctive  action  is 
an  adjustment  of  inner  to  outer  relations,  and  if  every 
rational  action  is  also  an  adjustment  of  inner  relations  to 
outer  relations ;  then,  any  alleged  distinction  can  have  no 
other  basis  than  some  difterence  in  the  characters  of  the 
relations  to_  which  the  adjustments  are  made.  It  must  be 
that  while,  in  Instinct,  the  correspondence  is  between  inner 
and  outer  relations  that  are  very  simple  or  general ;  in  Reason, 
the  correspondence  is  between  inner  and  outer  relations  that 
are  complex,  or  special,  or  abstract,  or  infrequent.  But  the 
complexity,  speciality,  abstractness,  and  infrequency  of  rela- 
tions, are  entirely  matters  of  degree.  .  .  .  How  then 
can  any  particular  phase  of  complexity  or  infrequency  be 
fixed  upon  as  that  at  which  Instinct  ends  and  Reason 
begins  ?  "f 

With  this  statement  I  quite  agree,  provided  I  am  allowed 

•  See  Principles  of  Psychology,  i,  pp.  253-71, 
t  Loc,  cd.,  pp.  453-4. 


.  r> '    » « - 


n 


BEASON. 


331 


to  make  the  important  addition  that  it  must  be  strictly 
limited  to  the  objective  aspect,  as  distinguished  both  from  the 
subjective  and  ejective  aspects  of  the  phenomena.  In  other 
words,  if  vre  have  regard  only  to  the  physical  aspect  of  the 
phenomena  {i.e.,  the  physiology  of  ganglionic  processes  as 
expressed  in  the  adjustive  movements  of  organisms),  this 
statement  of  the  case  is  unexceptionable.  But  if  we  pass 
from  physiology  to  psychology,  the  statement  ceases  to  be 
adequate ;  for  both  in  the  region  of  subjective  and  of  ejective 
psychology  it  would  fail  to  express  the  important  distinction 
between  two  very  different  acts  of  mind — viz.,  one  in  which 
there  is  no  knowledge  of  the  relation  between  means  em- 
ployed and  ends  attained,  and  one  in  which  there  is  such 
knowledge.* 

But,  passing  over  this  point,  we  arrive  at  a  lucid  state- 
ment of  the  view  that  "when  the  correspondence  has  advanced 
to  those  environing  objects  and  acts  which  present  groups  of 
attributes  and  relations  of  considerable  complexity,  and  which 
occur  with  comparative  infrequency — when,  consequently,  the 
repetition  of  experiences  has  been  insufficient  to  make  the 
sensory  changes  produced  by  such  groups  cohere  perfectly 
with  the  adaptive  motor  changes — when  such  motor  changes 
and  the  impressions  that  accompany  them  simply  become 
nascent:  then,  by  implication,  there  result  ideas  of  such 
motor  changes  and  impressions,  or,  as  already  explained, 
memories  of  the  motor  changes  before  performed  under  like 
circumstances,  and  of  the  concomitant  impressions."  Still 
there  is  not  yet  any  manifestation  of  rationality.  But  now, 
"  when  the  confusion  of  a  complex  impression  with  some 
allied  one  causes  a  confusion  among  the  nascent  motor  exci- 
tations, there  is  entailed  a  certain  hesitation,  and  .... 
ultimately  some  one  set  of  motor  excitations  will  prevail  over 
the  rest."  The  strongest  set  will  eventually  pass  into  action, 
and  as  this  set  will  usually  have  reference  to  the  circumstances 
which  have  recurred  most  frequently  in  experience,  "the 
action  will,  on  the  average  of  cases,  be  the  one  best  adapted 
to  the  circumstances.     But  an  action  thus  produced  is  nothing 

*  It  will  be  observed  that  if  we  adopt  Mr.  Spencer's  definition  of  Instinct, 
the  breach  on  the  mental  side  is  still  further  widened— the  distinction 
between  Instinct  and  Eeason  being  then  equivalent  to  the  distin(;tion  between 
nervous  actions  having  no  mental  counterparts  at  all,  and  nervous  SbCtiona 
which  on  their  subjective  side  are  inteationall^r  adaptive. 


833 


MENTAL  EVOLUTION  IN  ANIMALS. 


'     «\ 


IlKh 


II 


else  than  a  rational  one This,  however,  is  just 

the  process  which  we  saw  must  arise  whenever,  from  increas- 
ing complexity  and  decreasing  frequency,  the  automatic  adjust- 
ment of  inner  to  outer  relations  becomes  uncertain  and 
hesitating.  Hence  it  is  clear  that  the  actions  we  call  instinc- 
tive pass  gradually  into  the  actions  we  call  rational." 

Now  in  an  earlier  part  of  this  treatise  I  have  stated  my 
belief  that  consciousness  arises  when  a  nerve-centre  is  sub- 
jected to  a  comparative  turmoil  of  molecular  forces,  which 
finds  its  physiological  expression  in  delay  of  response,  or,  as 
Mr.  Spencer  says,  in  "  hesitation,"  But  I  do  not  believe  that 
in  all  such  cases  Eeason,  as  distinguished  from  Consciousness, 
must  arise.  Therefore  I  should  say  that,  although  there 
cannot  be  Eeason  without  such  ganglionic  friction,  there 
may  be  such  ganglionic  friction  without  Eeason.  There  may, 
for  example,  be  a  large,  and  even  a  distressing  amount  of 
such  friction  produced  in  the  case  of  a  conflict  of  instincts ; 
there  may  in  such  cases  be  prolonged  delay  ending  in  "  the 
strongest  group  of  antagonistic  tendencies  at  length  passing 
into  action ;"  and  yet  no  act  of  reason  need  arise. 

In  what  respect,  then,  do  I  diffier  from  Mr.  Spencer  touch- 
ing the  genesis  of  Eeason  ?  I  differ  from  him,  firstly,  in  not 
deeming  an  act  of  reason  as  such  a  constant  or  invariable 
index  of  ganglionic  disturbance  greater  than  that  which  may 
arise  under  other  circumstances  of  psychical  activity  (and 
therefore  in  not  deeming  that  reason  must  necessarily  arise  out 

7 of  such  disturbance);  and,  secondly,  in  not  deeming  that 
Eeas(*n  can  only  arise  out  of  Instinct. 

Taking  these  two  points  of  difference  separately,  it  will  be 
enough  to  say  of  the  first  that  it  has  reference  only  to  the 
earliest  origin  of  Eeason,  or  to  acts  of  reason  of  the  simplest 
kind ;  in  the  case  of  more  elaborate  processes  of  reasoning 
I  have  no  doubt  that  the  ganglionic  disturbance  must  be 
great,  and  that  without  such  disturbance  these  more  elaborate 
processes  would  not  be  possible.  But  this,  of  course,  is  a 
widely  different  matter  from  concluding  that  wherever  gan- 
glionic disturbance  reaches  a  certain  degree  of  complexity, 
leading  to  a  consequent  delay  of  response,  there  Eeason  (as 
distinguished  from  vividness  of  consciousness)  must  neces- 
sarily arise.  On  the  contrary,  I  hold  that  in  the  lower  stages 
of  what  I  have  defined  as  Eeason  (and,  a  fortiori,  in  all  the 
stages  of  what  I  have  defined  as  Inference),  there  may  not  be 


'the 


SEASON. 


333 


more,  and  there  may  not  be  even  so  much  ganglionic  dis- 
turbance or  consequent  delay  of  response,  as  there  may  be 
where  no  act  of  rationality  is  concerned — as,  e.g.,  in  a  conflict 
of  instincts. 

Turning  now  to  my  second  point  of  difference  with 
Mr.  Spencer,  I  can  see  no  adequate  ground  for  concluding 
with  him  that  Eeason  can  only  arise  out  of  Instinct.  On  the 
contrary,  holding,  as  I  have  explained,  that  Eeason  has  its 
antecedents  in  the  habitual  inferences  of  sensuous  perception, 
that  Instinct  (as  distinguished  from  Reflex  Action)  likewise 
has  its  antecedents  in  sensuous  perception,  and  that  neither 
Reason  nor  Instinct  can  advance  beyond  this  first  origin 
without  an  always  corresponding  advance  in  the  powers  of 
perception ;  holding  these  views,  I  am  forced  to  conclude  that 
Perception  is  the  common  stem  out  of  which  Instinct  and 
Reason  arise  as  independent  branches.  In  so  far  as  Percep- 
tion involves  Inference,  Instinct  involves  Perception,  and 
Reason  involves  Inference,  there  arises,  of  course,  a  genetic 
connection  between  Instinct  and  Reason  ;  but  this  connection 
is  clearly  not  of  the  kind  which  Mr.  Spencer  indicates :  it  is 
organic,  and  not  historic. 

This  important  divergence  in  my  views  from  those  of 
Mr.  Spencer  I  take  to  be  due  to  his  manner  of  regarding  the 
relations  that  subsist  between  nervous  changes  which  are 
accompanied  by  Consciousness,  and  nervous  changes  which 
are  not  so  accompanied.  Thus  the  divergence  between  our 
views  on  this  matter  began  so  far  back  as  in  our  respective 
analyses  of  Memory,  where  I  observed,  "  I  cannot  agree  that  if 
psychical  changes  (as  distinguished  from  physiological  changes) 
are  completely  automatic,  they  are  on  this  account  to  be 
precluded  from  being  regarded  as  mnemonic.  .  .  .  .  In 
so  far  as  they  involve  the  presence  of  conscious  recognition,  as 
distinguished  from  reflex  action,  so  far,  I  think,  no  line  of 
demarcation  should  be  drawn  between  them  and  any  less 
perfect  memories."*  Again,  the  divergence  was  manifested 
when  I  came  to  treat  of  Perception,  and  I  there  gave  my 
reasons  for  regarding  it  as  "  very  questionable  whether  the  only 
factors  which  lead  to  the  differentiating  of  psychical  processes 
from  reflex  nervous  processes  are  (as  Mr.  Spencer  alleges) 
complexity  of  operation  combined  with  infrequency  of  occur- 
rence."t    And  the  divergence  in  question  became  still  more 

•  See  p.  130.  t  See  p.  140. 

22  ^ 


'  1 1 

1 

. 

A 

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'       ■  i' 
t 

t 

1 

'■■{  I 


if 


.  '  :  I 

'  t 

i 
1  ' 

tl  1 

•■  H 

p'i 

334 


MENTAL  EVOLUTION  IN  ANIMALS. 


pronounced  when  I  arrived  at  my  analysis  of  Instinct ;  for 
by  identifying  Instinct  with  compound  reflex  action,  we  found 
it  to  be  evident  that  Mr.  Spencer  wholly  disregards  what  I 
take  to  be  the  essentially  distinguishing  feature  of  Instinct, 
viz.,  the  presence  of  Perception  .is  distinguished  from  Sensa- 
tion. Thus,  lastly,  when  we  now  come  to  the  province  of 
Eeason,  the  same  divergence  recurs.  Whether  for  the  special 
purpose  in  hand  I  accept  Mi'.  Spencer's  definition  of  Instinct 
as  coripound  reflex  action,  or  adhere  to  my  own  definition  of 
it  as  reflex  action  into  which  there  is  imported  the  element 
of  consciousness,  I  alike  find  it  impossible  to  agree  with 
him  that  Eeason  necessarily  and  only  arises  out  of  Instinct. 

For,  taking  first  Mr.  Spencer's  definition  of  Instinct,  I 
cannot  agree  that  Reason  necessarily  and  only  arises  out  of 
compound  reflex  action,  because  I  see  it  to  be  a  fact  that  in 
the  higher    organisms   we  meet    with  numerous  cases  of 
enormously  compound  reflex  actions  which  present  no  indi- 
cations of  rationality.     And  some  of  these  oases,  it  may  be 
parenthetically  observed,  can  nevfsr  at  any  period  of  their 
developmental  history  have  been  rational,  and  afterward^: 
have  become  automatic  by  frequency  of  repetition.     Such,  for 
example,  cannot  have  been  the  case  with  the  compound  reflex 
actions  which  are  concerned  in  parturition,  nor  with  those 
more  obscure  reflex  actions  which  now  bafhe  our  rationality 
to  comprehend — I  mean  the  changes  set  up  by  an  impreg- 
nated ovum  in  the  walls  of  the  uterus.     These  are  instances 
of  immensely  compound  reflex  actions  which  must  alway^3 
have  occurred  with  great  rarity  in  the  life-h  story  of  indi- 
viduals, and  can  never  at  any  time  have  been  either  the  causa 
or  the  effect  of  rationality. 

Again,  taking  my  own  definition  of  Instinct,  I  cannot 
agree  that  Reason  necessarily  and  only  arises  out  of  reflex 
action  into  which  there  is  imported  the  element  of  conscious- 
ness. For  this  element  is  merely  the  element  of  Perception, 
and  I  do  not  know  of  any  evidence  to  justify  the  conclusion 
that  Perception  can  only  arise  out  of  the  growing  complexity 
and  infrequency  of  reflex  actions.  As  I  said  in  my  chapter 
on  Perception,  "  the  truth  is  that,  so  far  as  definite  knowledge 
entitles  us  to  say  anything,  the  only  constant  physiological 
difference  between  a  nervous  process  accompanied  by  con- 
sciousness and  a  nervous  process  not  so  accompanied,  is  that 
of  time.    In  very  many  cases  no  doubt  this  difference  may 


SEASON. 


335 


be  caused  by  the  intricacy  or  the  novelty  of  the  nervous  pro- 
cess which  is  aeconipauied  by  consciousness;"*  but  seeing  that 
in  ourselves,  as  just  observed,  highly  intricate  and  very  infre- 
quent nervous  processes  may  take  place  mechanically,  I  do 
not  think  we  are  justified  in  concluding  that  complexity  and 
in  frequency  of  ganglionic  action  are  the  nnly  factors  in  deter- 
mining the  rise  of  consciousness.  But  even  supposing,  for 
the  sake  of  argument,  that  they  are,  still  it  would  not  follow 
that  the  only  road  to  Eeason  lies  through  Instinct.  Percep- 
tion being  the  element  common  both  to  Instinct  and  to 
Eeason,  it  may  very  well  happen  (and  ind -ed  I  think 
actually  does  happen)  that  Eeason  arises  directly  out  of  tho!,,a 
automatic  inferences  which,  as  we  have  seen,  are  given  in 
Perception,  and  which,  as  we  have  also  seen,  furnish  the  con- 
ditions to  the  origin  of  Instinct. 

From  this  statement,  however,  I  hope  it  will  be  manifest 
that  I  do  not  dispute  that  Eeason  may,  and  probably  does  in 
many  cases  arise  out  of  Instinct,  in  ihat  the  perceptive  basis 
of  Instinct  is  so  apt  to  yield  material  for  the  higher  percep- 
tions of  Eeason.  I  merely  object  to  the  doctrine  that  Eeason 
can  arise  in  no  other  way.  And,  as  further  showing  the 
untruth  of  this  doctrine,  I  may  in  conclusion  point  to  the 
numberless  instances  given  in  my  chapters  on  Instinct  of  the 
reciprocal  action  between  Instinct  and  Eeason — the  develop- 
ment of  the  former  sometimes  leading  to  the  higher  develop- 
ment of  the  latter  and  sometimes,  as  in  all  cases  of  the 
formation  of  Instinct  by  lapsing  intelligence,  the  development 
of  the  latter  leading  to  the  higher  development  of  the  former. 
Such  reciprocal  action  could  not  take  place  were  it  true  that 
Instinct  is  always  and  necessarily  the  precursor  of  Eeason. 

I  must  not  take  leave  of  this  discussion  on  Eeason  with- 
out briefly  alluding  to  the  very  prevalent  vlew-*-with  which  of 
course  I  do  not  agree — that  the  faculty  in  question  is  the 
special  prerogative  of  Man.  As  the  most  enlightened  and 
best  informed  writer  who  of  late  years  has  espoused  this 
doctrine  is  Mr.  Mivart,  I  shall  take  him  as  its  exponent,  and 
in  examining  his  arguments  on  the  subject  I  shall  consider 


argument? 


which  can  be 


that  I  am   examining  the   best 

adduced  in  support  of  the  view  in  question. 

Mr.  Darwin,  in  his  "  Descent  of  Man,"  gives  the  foUow- 

•  See  p.  140. 


>.■'!' 


lb  ' 


838 


MENTAL  EVOLUTION  IN  ANIMALS. 


ing  account  of  tho  exhibition  of  Keason  on  the  part  of  a 
Crab:—"  Mr.  Gardner,  whilst  watchini,'  a  shore  crab  (f/slasi- 
mus)  making  its  burrow,  threw  some  shells  towards  the  hole. 
One  rolled  in,  and  three  other  shells  remained  within  a  f(iW 
inches  of  the  mouth.  In  about  five  minutes  the  crab  brought 
out  the  shell  which  had  fallen  in,  and  carried  it  away  to  the 
distance  of  a  foot ;  it  then  saw  the  three  other  shells  lying 
near,  and  evidently  thinking  that  they  might  likewise  roll  iii^ 
carried  them  to  the  spot  where  it  had  laid  the  first.  It 
Avould,  I  think,  be  difficult  to  distinguish  this  act  from  one 
performed  by  man  by  the  aid  of  reason."* 

Mr.  Mivart,  after  quoting  the  above,  calls  the  concluding 
sentence  an  "astonishing  remark."!  I  shall,  therefore,  pro- 
ceed to  consider  the  very  prevalent  opinion  to  which  such  a 
commentary  introduces  us,  and  which  consists,  as  I  have  said, 
in  regarding  the  faculty  of  Eeason  as  the  special  prerogative 
of  Man. 

I  must  begin  by  again  observing  that  the  faculty  of 
Reason,  in  the  sense  of  a  "  knowledge  of  the  relation  between 
means  employed  and  ends  attained,  ....  admits  of 
numberless  degrees  ; "  and  I  hold  it  to  be  a  mistake,  greater 
than  any  other  that  has  been  committed  in  psychological 
science,  to  suppose  that  there  is  any  difference  of  kind 
whether  this  faculty  is  exercised  with  reference  to  the  highest 
abstractions  of  introspective  thought,  or  to  the  lowest  pro- 
ducts of  sensuous  perception ;  whether  the  ideas  involved  are 
general  or  special,  complex  or  simple,  wherever  there  is  a 
process  of  inference  from  them  which  results  in  establishing 
a  proportional  conclusion  among  them,  there  we  have  some- 
thing more  than  the  mere  association  of  ideas;  and  this 
something  is  Eeason.  If  I  were  to  see  a  large  stone  falling 
through  the  roof  of  my  conservatory,  and  on  climbing  to  the 
wall  above  saw  three  or  four  other  stones  just  upon  the  edge, 
I  should  infer  that  the  stones  which  fell  previously  stood  In 
a  similar  relation  to  my  conservatory,  and  therefore  that  it 
would  be  desirable  to  remove  the  others  from  their  threaten- 
ing position.  This  would  not  be  an  act  of  association,  but  an 
act  of  reason  (though  a  simple  one),  and  it  is  psychologically 
identical  with  the  act  which  was  performed  by  the  crab. 

Further,  according  to  J.  S.  Mill,  "  all  inference  is  from 
paiticulars  to  particulars:  General  propositions  are  merely 

•  Desuenl  of  Man,  p.  270.  f  Lessons  from  Nature,  p.  213. 


REASON. 


337 


registers  of  such  inferences  already  made,  and  short  formiilre 
for  making  more."      Now  although   this  doctrine   is    not 
universally   accepted  by  logicians— Whately,   for  instance, 
having  maintained   the   exact   converse,   and   many  minor 
writers  more  or  less  agreeing  with  him,— I  feel  compelled  to 
fall  in  with  it  on  purely  logical  grounds,  or  without  reference 
to  ariy  considerations  drawn  from  the  theory  of  evolution. 
For  it  appears  to  mo  that  Mill  is  completely  successful  in 
showing  that  only  by  this  doctrine  can  the  syllogism  be 
shown  to  have  any  functions  or  any  value.     "  It  must  be 
granted  that  in  every  syllogism,  considered  as  an  argument 
to  prove  the  conclusion,  there  is  a  pditio  princ'qni.    When 
we  say,  All  men  are  mortal;  Socrates  is  a  man;  therefore 
Socrates  is  mortal ;  it  is  unanswerably  urged  by  the  adver- 
saries of  the  syllogistic  theory  that  the  proposition,  Socrates 
is  mortal,  is  presupposed  in  the  more  general  assumption.  All 
men  are  mortal."    Therefore,  "  no  reasoning  from  generals  to 
particulars  can,  as  such,  prove  anything  :  since  from  a  general 
proposition  we  cannot  infer  any  particulars,  but  those  which 
the  principle  itself  assumes  as  known."    This  is  not  a  suit- 
able place  in  which  to  discuss  such  a  question  of  logic  at 
length,  and  therefore  I  shall  merely  refer  to  Mill's  exposition 
of  it*     But  as  I  can  see  no  escape  from  tlie  view  which  he 
enforces  that  the  major  premiss  of  a  syllogism  is  merely  a 
generalized  memorandum  of  past  particular  experiences,  and 
therefore  that  all  reasoning  is,  in  the  last  resort,  an  infer- 
ence from  particulars  to  particulars ;  I  think  that  this  con- 
clusion (arrived   at    without    reference    to    the    theory   of 
evolution)  is  available  to  argue  that  there  is  no  difference  in 
kind  between  the  act  of  reason  performed  by  the  crab  and 
any  act  of  reason  performed  by  a  man. 

It  must  be  remembered  that  I  am  not  now  discussing  the 
larger  question  as  to  whether  there  is  any  distinction  in  kind 
between  the  whole  mental  organization  of  an  animal  and  the 
whole  mental  organization  of  a  man.  This  larger  question  I 
shall  fully  discuss  in  my  subsequent  work.  Here  I  am  only 
endeavouring  to  show  that  so  far  as  the  particular  faculty  of 
mmd  is  concerned  which  falls  under  my  definition  of  reason, 
there  is  no  such  distinction.  A  process  of  conscious  infer- 
ence, considered  merely  as  a  process  of  conscious  inference, 


'I 


•    n 


*  Logic,  vol.  i,  Cliap.  IlL 


:;I1 


l!  i..  t* 


338 


MENTAL  EVOLUTION  IN  ANIMALS. 


;'. 


!'  iil 


.  \k     itii 


is  the  same  in  kind  wherever  it  occurs  and  whatever  degree 
of  elaboration  it  presents. 

But  here  I  must  meet  an  assertion  which  is  often  made, 
and  which  has  been  presented  by  Mr.  Mivart  with  his 
accustomed  adherence  to  logical  form,  and  therefore  with 
much  apparent  cogency.  He  says : — "  Two  faculties  are 
distinct  in  kind  if  we  may  possess  the  one  in  perfection 
without  thereby  implying  that  we  possess  the  other ;  and 
still  more  so  if  the  two  faculties  tend  to  increase  in  an 
inverse  ratio,  the  perfection  of  the  one  being  accompanied  by 
a  degradation  of  the  other.  Yet  this  is  just  the  distinction 
between  the  instinctive  and  rational  parts  of  man's  nature. 
His  instinctive  actions  are,  as  all  admit,  not  rational  ones ; 
his  rational  actions  are  not  instinctive.  Even  more  than  this, 
we  may  say  the  more  instinctive  a  man's  actions  the  Zess 
are  they  rational,  and  vice,  versd ;  and  this  amounts  to  a 
demonstration  that  reason  has  not,  and  by  no  possibility 
could  have  been,  developed  from  instinct.  In  man  we  have 
this  inverse  ratio  between  sensation  and  perception,  and  in 
brutes  it  is  just  where  the  absence  of  reason  is  most  generally 
admitted  {e.g.,  in  insects)  that  we  have  the  very  summit  and 
/  perfection  of  instinct  made  known  to  us  by  the  ant  and  the 
bee.  .  .  .  Sir  William  Hamilton  long  ago  called  atten- 
tion to  this  inverse  relation ;  but  when  two  faculties  tend  to 
increase  in  an  inverse  ratio,  it  becomes  unquestionable  that 
the  difference  between  them  is  one  of  kind."* 

Now  I  meet  this  argument  by  denying  the  alleged  fact  on 
which  it  reposes.  It  is  simply  not  true  that  there  is  any  con- 
stant inverse  ratio  of  the  kind  stated.  It  is  no  doubt  true  in  a 
general  way  (as  the  principles  of  evolution  would  lead  us  to 
anticipate),  that  as  animals  advance  in  the  scale  of  mental 
development  their  powers  of  intelligent  adjustment  are  apt 
to  become  added  in  larger  measure  to  their  less  elaborate 
powers  of  instinctive  adjustment;  but  that  there  is  no  inverse 
proportion  between  the  tv;o  must  be  evident  to  any  one  who 
has  directed  his  attention  to  the  mental  endowments  of 
animals.  Thus,  so  far  is  it  from  being  the  case  that  "  the 
absence  of  reason  is  most  generally  admitted"  among  the 
ants  and  bees,  that  all  the  observers  with  whose  writings  I 
am  acquainted  are  unanimous  in  their  opinion  that  there  are 
no  animals  among  the  Invertebrata  which  can  be  said  to 

•  Lessonn  from  Nature,  pp.  230-1. 


/«) 


\\i' 


li 


REASON. 


tltJU 


equal  the  ants  and  bees  in  respect  of  drawing  intelligent 
inferences.  Furthermore,  looking  to  the  animal  kingdom  as 
a  whole,  I  should  say  that  while  there  is  no  very  constant 
relationship  between  the  powers  of  instinct  and  those  of 
intelligent  inference,  such  relationship  as  tliere  is  points 
rather  to  the  view  that  the  complexity  of  mental  organization 
which  finds  expression  in  a  high  development  of  the  instinc- 
tive faculties,  is  favourable  to  the  development  of  the  more 
intelligent  faculties*  And  that  there  should  be  such  a 
general  correspondence  is  no  more  than  the  theory  of  evolu- 
tion might  lead  us  to  expect ;  for  the  progressive  complica- 
tion of  instincts  tends  to  diminish,  as  Mr.  Spencer  observes, 
their  purely  automatic  character.  But,  on  the  other  hand, 
that  this  correspondence  should  be  general  and  not  constant 
might  also  be  anticipated,  seeing  that  instincts  may  arise 
either  without  the  precedence  of  intelligence,  or  by  means  of 
the  lapsing  of  intelligence. 

In  the  next  place,  as  regards  Man,  I  do  not  think  that 
Mr.  Mivart's  argument  is  any  more  satisfactorily  established 
by  fact.  It  is  no  doubt  true  that  "  the  more  instinctive  are  a 
man's  actions  the  less  are  they  rational,  and  vice  versd;"  but 
this,  again,  is  no  more  than  we  should  expect,  on  the  hypo- 
thesis of  human  instincts  being  due  to  hereditary  experience, 
while  processes  of  conscious  inference  are  chiefly  due  to  indi- 
vidual experience.  It  thus  happens  that  the  instinctive 
actions  preponderate  over  the  intelligent  actions  during 
infancy,  and  that  the  scale  begins  to  turn  during  childhood. 
But  in  all  this  there  is  nothing  to  show  that  the  two  are 
distinct  in  kind ;  and  in  subsequent  life  their  generic  identity 
is  shown  by  the  fact  that  the  principle  of  lapsing  intelligence 
may  cause,  even  in  the  experience  of  the  individual,  actions 
which  are  at  first  consciously  adaptive  or  rational  to  become 
by  repetition  automatic  or  instinctive. 

To  what  misconception,  then,  are  we  to  ascribe  the  very 
prevalent  doctrine  that  Eeason  is  the  special  prerogative  of 
Man?  I  think  the  misconception  arises  from  an  erroneous 
meaning  which  is  attached  to  the  word  Reason.  Mr.  Mivart,  for 
instance,  habitually  follows  the  traditional  usage  and  invests 
the  word  with  the  meaning  that  belongs  to  self-conscious 
Thought.    Thus  he  expressly  says  that  in  denying  Eeason  to 

*  Cf.  Pouchet,  "L' Instinct  chez  les  Insedes,"  in  Eev.  des  Deux  Monties 
Feb.  1670,  p.  U'JO. 


1 1. : 


'M 


1      •!    ' 
i        I'  I 


II  'I 


340 


MENTAL  EVOLUTION  IN  ANIMALS. 


11 


brutes  all  he  maintains  is  that  "  they  have  not  the  power  of 
forming  judgments;"*  that  is,  in  his  own  definition  of  a 
judgment,  the  power  of  reflective  or  self-conscious  Thought. 
In  my  subsequent  work  I  shall  have  much  to  say  upon  the 
psychology  of  Judgment ;  but  here  it  is  enough  to  observe 
that  I  hold  the  power  of  reflective  thought,  which  the  forma- 
tion of  a  judgment  implies,  to  constitute  no  essential  part  of 
a  process  of  reason  as  such,  although  when  present  it  unques- 
tionably afibrds  that  process  much  new  material  with  which  to 
be  concerned.  As  I  have  said,  I  regard  reasoning  to  be  a  process 
of  consciously  inferring,  and  therefore  conclude  that  it  should 
make  no  difference  to  our  classification  of  the  rational  faculty 
whether  the  subject  matter  on  which  it  may  happen  to  be 
exercised  has  reference  to  the  sphere  of  feeling  or  to  that  of 
thought.  And,  as  Mr.  Mivart  allows  that  animals  perform 
"  practical  inferences,"  I  further  conclude  that  my  difference 
with  the  school  which  he  represents  has  reference,  so  far,  only 
to  a  matter  of  terminology.  There  is,  without  question,  some 
enormous  distinction  between  the  psychology  of  man  and 
that  of  the  lower  animals,  and  hereafter  I  shall  have  to 
consider  at  much  length  what  this  distinction  is.  Here  I 
am  only  concerned  with  showing  that  it  does  not  consist  in 
animals  having  no  vestige  of  the  faculty  of  Eeason  in  the 
sense  above  defined.  And,  in  order  to  show  this,  I  feel,  as  I 
have  already  remarked,  that  it  would  be  superfluous  to  render 
specific  instances  of  the  display  of  animal  reason ;  for  they 
have  already  been  given  in  such  abundance  in  my  former 
work. 


ft '  m\ 


"  Is  not  the  earth 
With  various  living  creatures,  and  the  air 
Eeplenished?     ....     know'st  thou  not 
Their  language  and  their  ways  ?     They  also  know 
And  reason  not  contemptibly." — Milton, 


i  I 


|i 


•  Lessons  from  Nature,  p.  217. 


I .. 


tr 


EMOTIONS. 


341 


i 


CHAPTER  XX. 


■|  •'1 


Animal  Emotions,  and  Summary  of  Intellectual 

Faculties. 


It  will  be  observed  on  turning  to  the  diagram  that  I  attribute 
to  animals  the  following  emotions,  which  I  name  in  the 
probable  order  of  their  historical  development: — Surprise, 
Fear,  Sexual  and  Parental  Affection,  Social  Feelings,  Pug- 
nacity, Industry,  Curiosity,  Jealousy,  Anger,  Play,  Atfection, 
Sympathy,  Emulation,  Pride,  Resentment,  Esthetic  Love 
of  Ornament,  Terror,  Grief,  Hate,  Cruelty,  Benevolence, 
Revenge,  Rage,  Shame,  Remorse,  Deceit,  Ludicrous.  This  list, 
which  leaves  many  of  the  human  emotions  without  men- 
tion, exhausts  all  the  emotions  of  which  I  have  found  any 
^evidence  in  the  psychology  of  animals.  Before  presenting 
this  evidence  in  detail,  perhaps  it  will  not  be  thought 
superfluous  again  to  insist  that  in  attributing  this  and 
that  emotion  to  such  and  such  an  animal,  we  can  depend 
only  upon  inference  drawn  from  actions,  and  that  this 
inference  necessarily  becomes  of  less  and  less  validity  as  we 
pass  through  the  animal  kingdom  to  organisms  less  and  less 
like  our  own ;  so  that,  for  instance,  "  when  we  get  as  low 
down  as  the  insects,  I  think  the  most  we  can  confidently 
assert  is,  that  the  known  facts  of  human  psychology  furnish 
the  best  available  pattern  of  the  probable  facts  of  insect 
psychology."*  Still,  as  the  known  facts  of  human  psychology 
do  furnish  the  best  available  pattern,  we  must  here,  while 
treating  of  the  emotional  faculties,  follow  the  same  method 
which  we  have  hitherto  followed  while  treating  of  the  intel- 
lectual faculties — viz.,  while  having  full  regard  to  the  pro- 
gressive weakening  of  the  analogy  from  human  to  brute 
psychology  as  we  recede  through  the  animal  kingdom  down- 
wards from  man,  nevertheless  using  the  analogy  so  far  as  it 
goes  as  the  only  instrument  of  analysis  that  we  possess. 

*  Animal  Intelligence,  pp.  9-10,  where  Bee  for  a  more  full  discussion  of 
this  point. 


' ' 


342 


MENTAL  EVOLUTION  IN  .VNIMALS. 


f 


m  Mi 


I  shall  now  proceed,  as  briefly  as  possible,  to  render  the 
evidence  which  hps  induced  me  to  ascribe  each  of  the  above- 
named  emotions  to  animals,  and  remembering  that  I  have  in 
each  case  written  the  emotion  upon  the  diagram  at  the  level 
•  of  mental  evolution  where  I  have  found  the  earliest  evidence 
of  its  occurrence,  it  follows  that  in  the  majority  of  cases  the 
emotion  is  present  in  the  higher  levels  of  mental  evolution 
in  a  more  highly-developed  form. 

It  will  be  observed  that  in  the  diagram  I  represent  the 
Emotions  as  a  class  to  take  their  origin  from  the,  growing 
structure  of  mind  at  the  same  level  as  that  at  which  the 
faculty  of  Perception  takes  its  origin.  I  do  this  because  I 
think  that  as  soon  as  an  animal  or  a  young  child  is  able  to 
perceive  its  sensations,  it  must  be  able  to  perceive  pleasures 
and  pains ;  hence,  when  the  antecedents  of  a  painful  percep- 
tion recur  in  consciousness,  the  animal  or  child  must  anticipate 
the  recurrence  of  that  perception — must  suffer  an  ideal 
representation  of  the  pains,  and  such  suffering  is  Fear.  And 
that,  as  a  matter  of  fact,  Fear  of  this  low  or  vague  order  is 
manifested  at  about  ':he  second  or  third  week  of  infancy,  is 
the  general  opinion  of  those  who  have  most  carefully 
observed  the  development  of  infant  psychology.*  To  specify 
the  class  in  the  animal  kingdom  where  a  true  emotion  of 
Fear  first  arises  is  clearly  a  more  difficult  matter,  and  indued 
it  is  impossible  to  do  so  in  the  absence  of  any  definite  know- 
ledge as  to  the  class  in  which  Perception  first  arises.  But  while, 
as  previously  (  x^lained,  I  am  not  able  to  say  whether  or  not 
the  Coelenterata,  and  still  less  the  Echinodermata,  are  able  to 
perceive  their  sensations,  I  think  the  evidence  becomes  very 
strong  in  the  case  of  insect  Larvae  and  Worms.  And  that  both 
the  one  and  the  other  manifest  striking  symptoms  of  alarm 
m  the  presence  of  danger  may  be  easily  shown.  For  instance, 
a  few  months  ago  I  had  an  opportunity  of  observing  the 
habits  of  the  processional  caterpillar  mentioned  in  "  Animal 
Intelligence."t    Wishing  to  ascertain  whether  I  could  artifi- 

•  See  Preyer,  loc.  cit. 

t  Pp.  238-40.  It  will  be  seen  on  referring  to  this  passage  that  D« 
Villiers'  account  difPers  materially  from  that  of  Mr.  Davis.  For  he  says  that, 
on  removing  one  of  the  chain  of  caterpillars,  the  whole  chain  stopped  imme- 
diately with  one  consent,  like  a  single  organism.  Mr.  Davis  on  the  other 
hand  said  that  the  information  was  communicated  from  caterpillar  to  cater- 
pillar at  the  rate  of  somewliat  less  than  a  second  per  caterpillar.  On  repeat- 
ing this  observation  a  great  number  of  times,  I  could  obtain  no  corroboration 
at  all  of  De  Villiers'  statement,  while  I  found  that  of  Mr.  Davis  to  be  correct 


EMOTIONS. 


343 


cially  imitate  the  stimulus  which  the  head  of  one  caterpillar 
supplied  to  the  tail  of  the  next  in  the  series  (and  which 
serves  to  let  the  latter  known  that  the  series  is  not  inter- 
rupted), I  removed  the  last  member  of  the  series.     As  always 
happens  when  this  is  done,  the  next  member  stopped,  then 
the  next,  and  the  next,  and  so  on,  till  the  whole  series  were  at 
a  halt.     If  I  had  now  replaced  the  last  member  with  its  head 
touching  the  tail  of  the  penultimate  member,  the  latter  would 
again  have  begun  to  move,  then  the  next,  and  the  next,  and 
so  on,  till  the  whole  series  would  again  have  been  in  motion. 
Instead  of  doing  this,  however,  I  took  a  camel-hair  brush  and 
gently  brushed  the  tail  of  the  then  last  member.     Imme- 
diately this  member  again  began  to  move,  and  so  set  the 
whole  train  again  upon  the  march.     But  in  order  that  the 
march  should  continue,  it  was  necessary  that  I  should  con- 
tinue brushing  the  tail  of  the  last  member.    Now  I  found 
that  if  I  brushed  in  the  least  degree  too  hard,  so  as  not  suffi- 
ciently well  to  imitate  the  stimulus  supplied  by  the  hairy 
head  of  a  caterpillar,  the  animal  became  alarmed  and  threw 
itself  upon  its  side  in  the  form  of  a  coil.     I  therefore  tried 
the  experiment  of  puzzling  the  animal,  by  first  brushing  its 
tail  gently  for  a  considerable  time— so  that  it  should  have  no 
reason  to  doubt,  as  it  were,  that  I  was  a  caterpillar— and 
then  beginning  by  degrees  to  brush  it  more  and  more  strongly. 
I  could°then  see  that  a  point  came  at  which  the  animal  was 
puzzled,  so  that  it  hesitated  whether  to  go  on  or  to_  throw 
itself  upon  its  side.     It  appeared  to  me  that  at  this  point  the 
animal  began  to  become  alarmed ;  for  the  brushing  was  still 
exceedingly  gentle,  so  that  if  the  animal  were  actuated  only 
by  a  pure  reflex  mechanism,  I  should  not  have  expected  so 
infinitesimally  small  a  difference  in  the  amount  of  stimula- 
tion to  produce  so  great  a  difference  in  the  nature  of  the 
response. 

in  all  particulars.  I  am  likewise  able  to  confirm  all  the  other  points  in  his 
account  of  the  remarkable  habits  of  these  larvro.  I  may  add  that  as  soon  as 
a  member  of  a  moving  chain  is  removed,  the  next  member  m  advance  not 
only  stops,  but  begins  to  wag  its  head  in  a  peculiar  manner  from  side  to  side. 
This  perhaps  may  serve  as  a  signal  to  the  next  member  to  stop;  but, however 
this  may  be,  as  soon  as  the  next  one  does  stop,  it  also  begins  to  wag  its  head 
in  the  same  manner,  and  so  on  till  aU  the  caterpillars  in  advance  of  the 
interruption  are  standing  still  and  wagging  their  heads.  And  they  aU 
continue  without  interruption  thus  to  wag  their  heads  untd  the  procession 
again  begins  to  move.  I  have  never  seen  this  pecuhar  movement  perfomed 
except  under  these  circumstances. 


m 

■j  '■ 

■  itsi 


I     i 

!   I 


344 


MENTAL  EVOLUTION  IN  ANIMALS. 


Agam  as  regards  Worms,  Mr.  Darwin  has  shown  in  hia 
work  on  the  Earth-worm  that  this  animal  is  of  a  "  timid " 
disposition,  darting  into  its  burrow  "like  a  rabbit"  when 
alarmed  Probably  other  kinds  of  worms,  which  are  better 
provided  with  organs  of  special  sense  and  consequently  have 
more  intelligence,  may  have  more  emotion. 

With  reference  to  young  children,  Preyer  is  of  the  opinion 
that  the  earliest  emotion  is  one  of  surprise  or  astonishment 
upon  perceiving  any  change,  or  strikingly  novel  feature,  in  the 
environment.  In  deference  to  his  opinion,  therefore,  I  have 
placed  Surprise  upon  the  same  level  of  emotional  develop- 
ment as  Fear ;  but  of  course  in  both  cases  this  level  is  so 
low  that  it  is  but  the  germs  of  such  emotions  that  are  here 
supposed  to  be  present. 

This  earliest  stage  of  emotional  development  (18)  I  have 
made  to  correspond  with  "  Emotions  preservative  of  Self." 
The  next  stage  (19)  I  make  to  coincide  with  the  origin  of 
"  Emotions  preservative  of  Species ; "  and  of  these  the  first 
to  appear  are  the  Sexual.  In  the  animal  kingdom— or 
rather  let  us  say  in  the  psychological  scale— these  emotions 
are  first  unequivocally  exhibited  by  the  Mollusca,*  which  on 
this  account,  as  well  as  for  the  reasons  given  while  treatint? 
of  the  association  of  ideas,  I  have  made  to  fill  the  corre- 
sponding level  on  the  other  side  of  the  diagram. 

The  next  level  (20)  is  occupied  by  Parental  Affection,  Social 
Feelings,  Pugnacity,  Emotions  conducing  to  Sexual  Selection, 
Industry,  and  Curiosity.  The  level,  therefore,  corresponds 
with  the  origin  of  the  branch  marked  Social  Emotions  in  the 
central  psychological  tree,  and  with  the  earliest  Ptecognition 
of  Offspring  on  the  side  of  the  intellectual  faculties.  The 
animals  which  first  satisfy  all  these  conditions  are  the  Insects 
and  Spiders.t  For  here,  even  if  we  exclude  the  Hymenoptera, 
we  have  evidence  of  parental  affection  in  the  care  which 
spiders,  earwigs,  and  sundry  other  insects  take  of  their  eggs 
and  broods.f  Again,  numberless  species  of  insects  are  highfy 
social  in  their  habits ;  others  are  highly  pugnacious ;  some 
are  conspicuously  industrious  ;t  most  flying  insects  (as  we 
have  already  seen  in  Chapter  XVIII)  display  curiosity ;  and, 
according  to  Mr.  Darwin's  elaborate  enquiries,  it  is  also  in 

•  See  Animal  Intelligence,  p.  26. 

t  For  remarkable  instances  of  this  see  ibid.,  p.  205  and  n  229 

X  Ibid.,  pp.  22t)-8.  '^' 


'  ruM 


EMOTIONS. 


845 


this  class  that  we  find  the  earliest  evidence  of  sexual  selec- 
tion. 

Coming  now  to  level  21, 1  have  assigned  to  it  the  first 
appearance  of  the  emotions  of  Jealousy,  Anger,  and  Play, 
which  unquestionably  occur  in  Fish.*  On  level  23  I  have 
placed  the  dawn  of  Affection  other  than  sexual,  in  view 
of  the  evidence  of  the  emotional  attachment  of  a  python 
which  was  exhibited  towards  those  who  had  kept  it  as  a 
pet.t 

On  level  24  I  have  placed  the  dawn  of  Sympathy,  seeing 
that  this  emotion  appears  to  be  unquestionably,  though  very 
fitfully,  displayed  by  the  Hymenoptera,t  which  for  other 
reasons  I  have  felt  obliged  to  assign  to  this  comparatively 
high  stage  of  psychological  development. 

On  the  next  level  (25)  I  have  given  Emulation,  Pride, 
Resentment,  ^Esthetic  Love  of  Ornament,  and  Terror  as  dis- 
tinguished from  Fear.  All  these  emotions,  so  far  as  I  have 
been  able  to  ascertain,  first  occur  in  Birds ;  and  in  this 
class  some  of  the  emotions  which  I  have  already  named  as 
occurring  in  lower  classes,  are  much  more  highly  developed.  § 

Next  we  arrive  at  Grief,  Hate,  Cruelty,  and  Benevolence, 
as  first  displayed  in  some  of  the  more  intelligent  of  the  Mam- 
malia. Grief  is  shown  by  pining,  even  to  death,  upon  the 
removal  of  a  favourite  master  or  companion ;  Hate  by  per- 
sisting resentment ;  Cruelty  by  a  cat's  treatment  of  a  mouse  ;|| 
and  Benevolence  by  the  following  instances  which  I  have 
met  with  since  the  publication  of  "  Animal  Intelligence." 
Writing  of  a  domestic  cat,  Mr.  Oswald  Fitch  says  that  it 
"  was  observed  to  take  out  some  fish-bones  from  the  house  to 
the  garden,  and,  being  followed,  was  seen  to  have  placed  them 
in  front  of  a  miserably  thin  and  evidently  hungry  stranger 
cat,  who  was  devouring  them ;  not  satisfied  with  that,  our  cat 
returned,  procured  a  fresh  supply,  and  repeated  its  charitable 
offer,  which  was  apparently  as  gratefully  accepted.  This  act 
of  benevolence  over,  our  cat  returned  to  its  customary  dining- 
place,  the  scullery,  and  ate  its  own  dinner  off  the  remainder 

*  See  Animal  Intelligence,  pp.  212-47. 

t  Ibid.,  pp.  261-2. 

j  Ibid.,  pp.  48-9  and  p.  156. 

§  Ibid.,  pp.  270-82.  Birds  are  the  lowest  animals  wliicli  I  have  myself 
Been,  or  have  heard  of  others  havin";  seen,  to  die  of  fright. 

II  For  instances  of  all  these  facts  in  Mammals  other  than  Elephants, 
Dogs  or  Monkeys,  see  Animal  Intelligence, 


m 


;1        S| 


m 


m 


If 


346 


MENTAL  EVOLUTION  IN  ANIMALS. 


of  the  bones,"*    An  almost  precisely  similar  case  has  been 
independently  communicated  to  me  by  Dr.  Allen  Thomson, 
r.E.S.     The  only  difference  was  that  Dr.  Thomson's  cat  drew 
the  attention  of  the  cook  to  the  famishing  stranger  outside  by 
pulling  her  dress  and  leading  her  to  the  place.    When  the 
cook  supplied  the  hungry  cat  with  some  food,  the  other  one 
paraded  round  and  round  while  the  meal  was  being  discussed, 
purring  loudly.     One  further  instance  of  the  display  of  bene- 
volent feeling  by  a  cat  will  suffice.     Mr.  H.  A.  Macpherson 
writes  me  that  in  1876  he  had  an  old  male  cat  and  a  kitten 
aged  a  few  months.     The  cat,  who  had  long  been  a  favourite, 
was  jealous  of  the  kitten  and  "  showed  considerable  aversion 
to  it."     One  day  che  floor  of  a  room  in  the,  basement  of  the 
house  was  partly  taken  up  in  order  to  repair  some  pipes.  The 
day  after  the  boards  had  been  replaced,  the  cat  "  entered  the 
kitchen  (he  lived  almost  wholly  on  the  drawing-room  floor 
above),  rubbed  against  the  cook  and  mewed  without  ceasing 
until  he  had  engaged  her  attention.     He  then,  by  running  to 
and  fro,  drew  her  to  the  room  in  which  the  work  had  taken 
place.     The  servant  was  puzzled  until  she  heard  a  faint  mew 
from  beneath  her  feet.     On  the  boards  being  lifted  the  kitten 
emerged  safe  and  sound,  though  half-starved.  The  cat  watched 
the  procc3dings  with  the  greatest  interest  until  the  kitten  was 
released  ;  but  on  ascertaining  that  it  was  safe  he  at  once  left 
the  rooir;,  without  evincing  any  pleasure  at  its  return.    Nor 
did  he  subsequently  become  really  friendly  with  it." 

On  the  next  level  I  have  placed  Eevenge  as  distinguished 
from  Eesentment,  and  Eage,  as  distinguished  from  Anger. 
In  "  Animal  Intelligence "  I  give  some  cases  of  apparent 
vindictiveness  occurring  in  birds  ;t  but  as  the  exact  nature  of 
the  emotions  in  these  cases  appears  to  me  someM'^hat  doubtful, 
I  here  disregard  them,  and  place  Eevenge  on  the  psycholo- 
gical level  which  is  occupied  by  the  Elephant  and  Monkeys, 
in  which  animals  this  passion  is  very  conspicuous.|  The 
same  remarks  apply  to  Eage,  as  distinguished  irom  the  less 
violent  display  of  hostile  feeling  which  is  suitably  expressed 
by  the  term  Anger. 

Lastly,  at  level  28  we  arrive  at  the  highest  products  of 
emotional  development  which  are  manifested  in  animal 
psychology,  and  therefore  at  the  highest  of  those  products 


•  Nature,  April  19,  1883,  p.  580. 

X  Animal  Intelligence,  pp.  i587-8  and  478. 


t  Pp.  277-8. 


EMOTIONS. 


347 


with  which  the  present  treatise  is  concerned.  These  are 
Shame,  Eemorse,  Deceit,  and  the  Emotion  of  the  Ludicrous. 
For  instances  of  the  display  of  these  emotions  by  Uogs  and 
Apes,  I  need  merely  again  refer  to  "  Animal  Intelligence."* 

In  this  brief  sketch  of  the  emotional  faculties  as  they 
occur  in  the  animal  kingdom,  my  aim  has  been  to  give  a 
generic  rather  than  a  specific  representation.  I  have  there- 
fore omitted  all  details  of  the  emotional  character  of  this  and 
that  particular  animal,  as  well  as  the  narration  of  particular 
instances  of  the  display  of  emotions.  Such  details  and  par- 
ticular instances  will  be  found  in  sufficient  abundance  in  my 
previous  work,  and  it  seems  undesirable,  for  the  larger  purpose 
now  in  hand,  either  to  repeat  what  I  have  said  before,  or  to 
burden  the  discussion  with  additional  facts  serving  only  to 
corroborate  the  general  assignment  of  levels  which  I  have 
now  given. 

Before  concluding  the  present  chapter,  and  with  it  the 
present  work,  I  shall  give  a  similar  outline  sketch  of  the 
assignment  of  levels  on  the  other  and  corresponding  side  of 
the  diagram,  which  serves  to  show  the  probable  history  of 
mental  evolution  so  far  as  the  faculties  of  intellect  are  con- 
cerned. This,  of  course,  has  already  been  done  throughout 
the  course  of  all  the  preceding  pages ;  but  I  think  it  desirable 
to  terminate  our  analysis  of  the  psychology  of  animals,  by 
briefly  stating  in  a  serial  form  the  reasons  which  have  induced 
me  to  assign  the  various  classes  of  animals  to  the  levels  of 
psychological  development  in  which  I  have  respectively 
placed  them.  It  is  only  needful  to  premise  that  in  consider- 
ing this  side  of  the  diagram  I  shall  not  at  present  wait  to 
treat  of  the  column  which  has  to  do  with  the  psycho- 
genesis  of  the  child,  for  this  will  require  to  be  treated  ah 
initio  in  my  work  on  Mental  Evolution  in  Man.  I  may 
further  observe  that  the  sundry  psychological  faculties  which 
I  have  written  on  one  of  the  vertical  columns  are  intended  as 
so  many  indices  of  mental  evolution,  and  not  as  exhausting 
all  the  distinctions  between  one  level  of  such  evolution  and 
another.  Indeed,  looking  to  the  fact  that  our  classification  of 
faculties  is  conventional  rather  than  natural,  we  cannot  expect 
that  any  diagrammatic  representation  of  the  order  in  which 
they  have  been  developed  should  admit  of  being  made  very 
*  Pp.  438-45,  and  471-78  j  also  484-98. 


:    !■ 


:^i 


■vlW 


,!,  !     ,] 


!', 


?r,  I 


I'l  -^ 


343 


MENTAL  EVOLUTION  IN  ANIMALS. 


precise ;  for  in  some  existing  animals  certain  faculties  are 
more  highly  developed  than  they  are  in  other  existing 
animals,  which  nevertheless  wit),  i  ';^.xrd  to  their  general 
psychology  occupy  a  higher  levi'i  nf  menttil  evolution.  There- 
fore the  faculties  which  I  have  nam",t:I  in  the  vertical  column 
have  been  chosen  only  because  they  serve  as  convenient 
indices  to  mark  the  general  upward  progress  of  mental  evolu- 
tion in  the  animal  kingdom, 

I  have  already  sufficiently  expressed  my  doubt  as  to  the 
levels  at  which  all  animals  below  the  Artirul'i..  ti  ild  be 
placed,  and  I  have  explained  that  this  doubt  arises  from  the 
difficulty,  or  rather  the  impossibility  of  ascertaining  at  what 
grade  of  psychological  evolution  consciousness  first  occurs. 
The  positions,  therefore,  which  I  have  assigned  to  the  Ccelen- 
terata  and  Echinodermata  are  confessedly  arbitrary,  and  have 
been  determined  only  because  I  have  not  been  able  to  observe 
that  these  animals  give  any  unmistakable  evidence  of  percep- 
tion as  distinguished  from  sensation.  This  remark  applies 
especially  to  the  Ccelenterata,  which  in  my  opinion  present 
no  semblance  of  evidence  that  any  of  their  responsive  move- 
ments are  of  a  perceptive,  or  even  of  a  conscious  nature.  My 
judgment  with  respect  to  the  Echinodermata  is  less  confident, 
for  although  I  am  sure  that  I  am  right  in  placing  them  on  a 
higher  level  of  sensuous  capability  than  the  Ccelenterata,  I 
am  not  at  all  sure  that  I  ought  not  to  have  placed  them  one 
stage  higher  (i.e.,  on  18  instead  of  17),  so  as  to  have 
brought  them  within  the  first  rise  of  perception.  For  the 
"  acrobatic  "  and  "  righting "  movements  which  are  per- 
formed by  these  animals,  and  which  I  have  described  elsewhere, 
are,  to  say  the  least,  strongly  suggestive  of  true  powers  of 
perception.  It  is,  therefore,  on  the  principle  of  preferring  to 
err  on  the  side  of  safety  that  I  have  placed  the  Echinoder- 
mata on  level  17  and  not  on  level  18.  That  I  am  justified 
in  attributing  to  these  animals  faint  powers  of  memory  (as 
distinguished  from  the  association  of  ideas)  may,  I  think,  be 
shown  by  thr;  fact  that  when  a  star-fish  is  crawling  along  the 
perpendicular  wall  of  a  tank  at  the  level  of  the  surface  of  the 
water,  it  every  now  and  then  throws  back  its  rays  to  feel  for 
other  surfaces  of  attachment,  and  if  it  does  not  succeed  in 
finding  such  a  surface,  it  again  applies  its  rays  to  crawling 
along  the  side  of  the  tank  in  the  same  direction  as  before,  in 
order  that  it  may  again  and  again  repeat  the  manoeuvre  in 


KM0TI0N3. 


349 


long 


different  lof^alities.  Now,  as  this  manoeuvre  requires  a 
time  to  execute,  I  think  the  fact  that  after  it  lias  beeu 
executed  the  animal  continues  its  advance  in  the  same  direc- 
tion as  that  in  which  it  was  crawling  before  the  manoeuvre 
began,  constitutes  tolerable  evidence  in  favour  of  an  abidin" 
impression  upon  the  nerve-centres  concerned,  and  one  which 
assuredly  is  not  due  to  any  organically  imposed  conditions, 
seeing  that  on  no  two  occasions  is  the  manoeuvre  performed 
in  exactly  the  same  way,  or  even  at  the  same  intervals  of 
time. 

On  the  next  level  I  have  placed  Larvaj  of  Insects  and 
Annelida.  My  reason  for  doing  so  is  that  both  these  classes 
of  organisms  unquestionably  exhibit  instincts  of  the  primary 
kind,*  the  origin  of  which  is  also  assigned  to  this  level.  In 
both  cases,  however,  we  meet  with  certain  facts  which  may 
justly  lead  us  to  question  whether  in  these  animals  intelli- 
gence of  a  higher  order  may  not  be  present;!  but  liere  again 
I  think  it  is  better  to  err  on  the  safer  side. 

It  is  in  the  MoUusca  that  we  first  undoubtedly  meet  with 
a  demonstrable  power  of  learning  by  individual  experience,^ 
and  therefore  I  have  placed  this  class  of  animals  upon  the 
next  level,  which  is  occupied  by  the  first  appearance  of  the 
power  of  association  by  contiguity.  Of  course,  if  the  account 
given  by  Mr.  Lonsdale  to  Mr.  Darwin  of  the  pair  of  land- 
snails§  were  ever  to  be  corroborated  by  further  observations, 
the  Gasteropoda  would  require  to  be  separated  from  the' 
other  Mollusca  and  placed  on  a  higher  level  in  the  diagram, 
as  I  have  done  in  the  case  of  the  Cephalopoda. 

Next  we  come  to  Insects  and  Spiders  on  a  level  with  the 
first  Eecognition  of  Offspring  and  the  rise  of  Secondary 
Instincts.     The  evidence  that  both  these  faculties  occur  in 

both  these  divisions  of  the  Articulata  is  unquestionable 

and    this   even   when  the   Hymenoptera  are  removed  for 
separate  psychological  classification.!! 

Fish  and  Bntrachia  are  assigned  to  the  next  level  which 
corresponds  wi  a  the  rise  of  Association  by  Similarity,  which 
I  think  we  are  justified  in  first  ascribing  to  these  animals.! 

On  level  22  I  have  written  the  higher  Crustacea.     I 

•  See  Animal  Intelligence,  234-40,  and  24. 

t  Ibid.,  and  Mr.  Darwin's  work  on  Worms. 

X  Ibid.,  pp.  25-y.  §  Ibid.,  p.  27. 

(I  Ibid.,  pp.  207-222,  and  226-31.        H  Ibid.,  pp.  250-1,  and  255. 


m\ 


m 


350 


MENTAL  EVOLUTION  IN  ANIMALS. 


! 


'•'!('■ 


FIs  li 


1 1 


''  I 


I' 


have  done  so  because  this  is  the  stn^e  where,  from  inde- 
pendent considerations  already  explained,  I  have  assigned 
the  dawn  of  Reason  (as  distinguished  from  Inference),  and 
the  lowest  animal  psychologically  considered  in  which  I 
have  found  any  evidence  of  this  faculty  is  tlie  crab.* 

,  Next  we  come  to  level  23  where  I  have  placed  the 
Reptiles  and  Cephalopoda.  My  reason  for  so  doing  is  tiiat 
this  is  the  level  where  I  have  represented  psychological 
development  to  have  advanced  sufficiently  far  to  admit  of 
the  recognition  of  persons,  and  this  degree  of  advance  has 
undoubtedly  been  attained  by  the  Reptiles  and  the  Ccphalo- 
poda.t  It  will  be  observed  that  I  have  bracketed  this  and 
the  two  preceding  levels  togetber.  My  reason  for  doing  so 
is  that  the  animals  and  the  faculties  named  upon  these  levels 
in  some  degree  overlap.  Thus  the  Batrachia  are  able  to 
recognize  per.sons,t  and  it  is  possible  that  Fisli  may  be  able 
to  reason,§  while,  on  the  other  hand,  the  Reptiles  and  Cepha- 
lopoda are  not  in  their  general  psychology  so  far  above 
the  Batrachia  and  Fish  as  would  be  implied  without  the 
bracket ;  yet  I  should  not  be  justified  in  placing  them  all 
upon  the  same  level,  because  I  have  no  such  definite  evidence 
that  Batrachia  and  Fish  are  able  to  reason  as  I  have  in  the 
case  of  Crustacea,  Cephalopoda,  and  Reptiles.  On  the  whole, 
therefore,  I  think  that  the  fairest  mode  of  expressing  these 
various  cross  relations  is  the  one  v.'hich  I  have  adopted.  It 
is  not  to  be  expected  that  our  essentially  artificial  mode  of 
distinguishing  between  psychological  faculties  should  so  far 
agree  with  nature,  that  when  applied  to  the  animal  kingdom 
our  classification  of  faculties  should  always  be  found  exactly 
to  fit  with  our  classification  of  organisms,  so  that  every 
branch  in  our  psychological  tree  should  precisely  correspond 
with  some  branch  in  our  zoological  tree.  Some  amount  of 
overlapping  must  be  expected,  and  in  thus  comparing  the  one 
classification  with  the  other  my  only  surprise  has  been  how, 
in  a  general  way,  the  two  so  closely  coincide. 

On  level  24  I  have  placed  the  Hymenoptera,  together 
with  the  distinction  which  I  think  most  sharply  marks  off  this 
stage  of  mental  evolution,  i.e.,  the  power  of  communicating 
ideas — a  power  which  ants  and  bees  undoubtedly  possess.|l 


•  See  Animal  Intelligence,  p.  233. 
t  Ibid.,  pp.  259,  2G0-1,  and  30. 
II  Ibid.,  pp.  49-57,  and  156-60. 


X  Ihid.,  p.  255. 
§  Ibid.,  pp.  250-1. 


EMOTIONS. 


351 


Next  we  arrive  at  Birds  with  the  psychological  distinc- 
tion of  recognizing  pictorial  representations,  understanding 
words,  and  dreaming.*  If  any  of  these  faculties  occur  in 
any  of  the  lower  vertebrata,  I  have  not  found  evidence  of 
the  fact. 

To  the  next  level  I  have  assigned  the  Eodents  and  Carni- 
vora,  with  the  exception  of  the  dog.  The  most  marked 
psychological  distinction  which  I  take  to  mark  this  level  is 
the  understanding  of  mechanisms.  For,  although  I  have 
found  one  instance  of  such  understanding  to  occur  in  Birds.t 
and  although  it  likewise  unquestionably  occurs  in  Eumi- 
nants.t  in  neither  case  does  the  understanding  appear  to 
extend  further  than  to  the  simplest  order  of  mechanisms,  and 
therefore  is  only  comparable  in  kind  with  the  much  greater 
aptitude  in  this  respect  which  is  shown  by  rats,§  foxes,|} 
cat3,ir  and  the  wolverine.** 


\M 


•  Animal  Intelb'genee,  pp.  311-12.    t  Ihi^-,  p.  816.     J  Ihid.,  pp.  388-9. 

§  Ihid.,  p.  361.  II  Ibid.,  pp.  428-31.  f  ibid.,  pp.  420-22. 

•*  Ibid.,  pp.  848-50. — Sir  James  Paget  has  told  me  of  a  parrot  which  by 
attentive  study  learned  how  to  open  a  lock  j  but  although  such  cases  may 
occasionally  occur  in  birds,  they  are  so  comparatively  rare  that  I  have  thought 
it  best  to  place  the  faculty  of  appreciating  simple  mechanical  appliances  on 
the  next  level,  for  it  is  here  only  that  we  may  first  be  sure  that  the  actions 
are  not  due  to  mere  association.  A  cat  which  jumps  at  a  thumb-latch,  and 
while  holding  on  to  the  curved  handle  beneath  with  one  fore-leg,  depresses  the 
thumb-piece  with  the  other  and  pushes  the  door-posts  with  the  hind-leg, 
clearly  shows  that  she  has  an  intelligent  appreciation  of  the  facts  that  the 
latch  fastens  the  door,  that  when  it  is  depressed  the  door  will  be  liberated, 
and  that  when  then  pushed  the  door  will  open.  And  if  it  can  still  be  sup- 
posed that  all  this  knowledge  can  be  obtained  by  simple  association,  tl?ere 
is  the  yet  more  remarkable  case  of  the  monkey  described  in  Animal  Intelli- 
gence, which  by  patient  investigation  discovered  for  himself,  and  without  ever 
having  observed  any  one  perform  a  similar  action,  the  mechanical  principle 
of  the  screw,  not  to  say  also  of  the  lever. 

It  is  remarkable,  as  I  observed  in  Animal  Intelligence,  that  this  faculty 
of  appreciating  simple  mechanical  appliances  does  not  seem  always  to  stand 
in  any  very  precise  or  quantitative  relation  to  the  general  mental  develop- 
ment of  the  species  which  exhibit  it.  Thus  the  dog  is,  as  to  his  general  in- 
telligence, unquestionably  superior  to  the  cat,  and  yet  his  ability  Li  the 
particular  we  are  considering  is  certainly  not  so  high  ;  while  bovine  animals 
and  horses  seem  to  show  more  cleverness  in  this  respect  than  in  any  other. 
Probably  the  explanation  of  this  apparent  disproportion  in  the  development 
of  the  psychical  faculties  is  to  be  found  in  the  corporeal  members  which 
minister  to  them  ;  the  monkey,  which  shows  the  highest  power  of  appreciating 
mechanical  appliances,  is  the  animal  which  is  best  endowed  with  the  organs 
of  tactual  examination  ;  the  fore-paws  of  a  cat  are  better  instruments  in  this 
respect  than  those  of  the  dog  j  while  the  trunk  of  the  elephant,  the  lips  of 
the  horse,  and  horns  of  ruminants  give  them  in  the  same  respects  an  advantage 
over  most  other  mammals  of  a  comparable  grade  of  iotelligence. 


t  I 


■'  f 


352 


MENTAL  EVOLUTION  IN  ANIMALS. 


Next  we  arrive  at  Monkeys  and  the  Elephant,  which,  with 
the  exception  of  the  Anthropoid  Apes,  are  the  only  animals 
that,  so  far  as  I  have  been  able  to  ascertain,  make  use  of 
tools* 

Lastly  on  level  28  we  arrive  at  the  highest  development 
of  the  psychical  powers  which  are  to  be  met  with  in  existing 
animals,  and  to  this  level  I  have  assigned  the  Anthropoid 
Apes  and  Dogs.  The  meaning  of  the  term  "Indefinite 
Morality,"  which  I  give  as  distinctive  of  this  grade  of 
mental  evolution,  I  shall  explain  in  my  next  work,  when  I 
shall  have  to  discuss  the  question  touching  the  probable 
genesis  of  the  moral  sense.  It  is,  I  think,  undesirable  to 
divide  this  discussion,  and  therefore  I  prefer  to  postpone  the 
considerr.tion  of  this  which  I  take  to  be  the  earliest  phase  in 
the  development  of  the  faculty  of  Conscience.  And  for  the 
same  reason  I  shall  postpone  my  analysis  of  the  lower  stages 
of  Abstraction  and  Volition,  both  of  which  are  crossed  by 
the  level  which  we  have  now  reached,  where  our  enquiry 
into  the  Mental  Evolution  of  Animals  comes  to  an  end. 

•  Animal  Intelligence,  pp.  408-9  and  480-94. 


THE  END. 


A  POSTHUMOUS  ESSAY  ON  INSTINCT, 


BY 


CHARLES  DAKWIJSr,  M.A.,  LL.D.,  F.RS. 


APPENDIX. 


iffii„ 


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;*!< 


;      .  1 

■■  V 

f  I 

r-'  ■  ■      ■■ 

if 

i  I 

V 

1 

likM 

APPENDIX. 


[The  full  text  of  a  part  of  Mr.  Darwin's  chapter  on 
Instinct  written  for  the  "  Origin  of  Species,"  but  afterwards 
suppressed  for  the  sake  of  condensation.] 


itii 


Migration. — The  migration  of  young  birds  across  broad 
tracts  of  the  sea,  and  the  migration  of  young  salmon  from 
fresh  into  salt  water,  and  the  return  of  both  to  their  birth- 
places, have  often  been  justly  advanced  as  surprising  in- 
stincts. With  respect  to  the  two  main  points  which  concern 
us,  we  have,  firstly,  in  different  breeds  of  birds  a  perfect 
series  from  those  which  occasionally  or  regularly  shift  their 
quarters  within  the  same  country  to  those  which  periodically 
pass  to  far  distant  countries,  traversing,  often  by  night,  the 
open  sea  over  spaces  of  from  240  to  300  miles,  as  from  the 
north-eastern  shores  of  Britain  to  Southern  Scandinavia. 
Secondly,  in  regard  to  the  variability  of  the  migratory 
instinct,  the  very  same  species  often  migrates  in  one  country 
and  is  stationary  in  another ;  or  different  individuals  of  the 
same  species  in  the  same  country  are  migratory  or  stationary, 
and  these  can  sometimes  be  distinguished  from  one  another 
by  slight  differences.*  Dr.  Andrew  Smith  has  often  re- 
marked to  nie  how  inveterate  is  the  instinct  of  migration  in 
some  quadrupeds  of  S.  Africa,  notwithstanding  the  persecu- 
tion to  which  they  are  in  consequence  subjected:  in  N". 
America-  however,  persecution  has  driven  the  Bufi'alo  within 

*  Mr.  Gruld  has  observed  tliis  fact  in  Malta,  and  in  Tasmania  in  the 
Bouthern  hemisphere.  Eeehstein  {^Stuhenvogel,  1840,  s.  293)  says  that  in 
Germany  the  migratory  and  non-mignitory  Thrushes  can  be  distingmshed  by 
the  yellow  tinge  of  the  eoles  of  their  feet.  The  Quail  is  migratory  m 
S.  Africa,  but  stationary  in  Robin  Island,  only  two  leagues  from  the  con- 
tinent  {Le  Vaillani's  Travels,  vol.  i,  p.  105)  :  Dr.  Andrew  Smith  confirms 
this.  In  Ireland  the  Quail  has  lately  taken  to  remain  in  numbers  to  breed 
there  (W.  Thompson,  Nat.  Eist.  of  Ireland,  vide  "  Hirda,"  vol.  ii,  p.  70). 


t^il 


'  I' 


iri 


356 


MENTAL  EVOLUTION  IN  ANIMALS. 


Jill 


»  M' 


a  late  period*  to  cross  in  its  migrations  the  Eocky  Moun- 
tains ;  and  those  "  great  highways,  continuous  for  a  hundred 
'/miles,   always   several  inches,   sometimes    several    feet    in 

^  depth,"  worn  by  migrating  buffaloes  on  the  eastern  plains, 
are  never  found  westward  of  the  Eocky  Mountains.  In  the 
United  States,  swallows  and  other  birds  have  largely  ex- 
tended, within  quite  a  late  period,  the  range  of  their  migra- 
tions.t 

_  The  migratory  instinct  in  Birds  is  occasionally  lost ;  as 
m  the  case  of  the  Woodcock,  some  of  which  have  totally, 
without  any  assignable  cause,  taken  to  breed  and  become 
stationary  in  Scotland.^  In  Madeira  the  first  arrival  of  the 
Woodcock  is  known,§  and  it  is  not  there  migratory ;  nor  is 
our  common  Swift,  though  belonging  to  a  group  of  birds 
almost  emblematical  of  migration.  A  Brent  Goose,  which 
had  been  wounded,  lived  for  nineteen  years  in  confinement ; 
and  for  about  the  first  twelve  years,  every  spring  at  the 
migratory  period  it  became  uneasy,  and  would,  like  other 
confined  individuals  of  the  species,  wander  as  far  northwards 
as  possible ;  but  after  this  period  "  it  ceased  to  exhibit  any 
particular  feeling  at  this  season."||  So  that  we  have  seen 
the  migratory  impulse  at  last  worn  out. 

In  the  migration  of  animals,  the  instinct  which  impels 
them  to  proceed  in  a  certain  direction  ought,  I  think,  to  be 
distinguished  from  the  unknown  means  by  which  they  can 
tell  one  direction  from  another,  and  by  which,  after  starting, 
they  are  enabled  to  keep  their  course  in  a  dark  night  over 
the  open  sea ;  and  likewise  from  the  means— whether  some 

^  instinctive  association  with  changing  temperature,  or  with 
want  of  food,  &c.— which  leads  them  to  start  at  the  proper 
period.     In  this,  and  other  cases,  the  several  parts  of  the 

•  Col.  Fremont,  Report  of  Exploring  Expedition,  1845,  p.  144. 

+  See  Dr.  Biicbnian's  excellent  memoir  on  tliis  subject  in  SiUiman's 
F/iiiosoph.  Jourii.,  vol.  30,  p.  81. 

t  Mr.  W.  Tliompson  has  given  an  excellent  and  full  account  of  this 
^liole  subject  (see  Nat.  Hist,  of  Ireland,  "  Birds,"  vol.  ii,  pp.  247-57),  where 
he  discusses  the  cause.  There  seems  reason  to  believe  (p.  254)  that  tli- 
mi^'ratory  and  nor -migratory  individuals  can  be  distinguished.  For  Scotlaua 
see  St.  John  s  W..  i  Sports  of  the  Highlands,  1846,  p.  220. 

§  Dr.  Heiueken  in  Zoological  Journal,  vol.  v,  p.  75.     See  also  Mr  E    V 
Haicourt's  r/cetch  of  Madeira,  1851,  p.  120. 

II  W,  Thompson,  loc.  cit.,  vol.  iii,  p.  63.  In  Dr.  Bachman's  paper  iust 
refeiTftd  to  (^jisijs  of  Canada  geese  in  confinement  periodically  'rying  to  escape 
northward  are  giveu.  * 


APPENDIX. 


357 


problem  have  often  been  confused  together  under  the  word 
instiuct.*  With  respect  to  the  period  of  starting,  it  cannot 
of  course  be  memory  in  the  young  cuckoos'  start  for  the  first 
time  two  months  after  their  parents  have  departed :  yet  it 
deserves  notice  that  animals  somehow  acquire  a  surprisingly 
accurate  idea  of  time.  A.  d'Orbigny  shows  that  a  lame 
hawk  in  S.  America  knew  the  period  of  three  weeks,  and 
used  at  this  interval  to  visit  monasteries  when  food  was  dis- 
tributed to  the  poor.  Difficult  though  it  may  be  to  conceive 
how  animals  either  intelb'i^ently  or  instinctively  come  to 
know  a  given  period,  yet  we  shall  immediately  see  that  in 
some  cases  our  domestic  animals  have  acquired  an  annual 
recurring  impulse  to  travel,  extremely  like,  if  not  identical 
with,  a  true  migratory  instinct,  and  which  can  hardly  be  due 
to  mere  memory. 

It  is  a  true  instinct  which  leads  the  Brent  Goose  to  try  to 
escape  northwards ;  but  how  the  bird  distinguishes  north  and 
south  we  know  not.  Nor  do  we  know  how  a  bird  M'^hich 
starts  in  the  night,  as  many  do,  to  traverse  the  ocean,  keeps 
its  course  as  if  provided  with  a  compass.  But  we  should  be 
very  cautious  in  attributing  to  migratory  animals  any 
capacity  in  this  respect  which  we  do  not  ourselves  possess  ;t 
though  certainly  in  them  carried  to  a  wonderful  perfection. 
To  give  one  instance,  the  experienced  navigator  WrangelJ 
expatiates  with  astonishment  on  the  "  unerring  instinct "  of 
the  natives  of  N.  Siberia,  by  which  they  guided  him  through 
an  intricate  labyrinth  of  hummocks  of  ice  with  incessant 
changes  of  direction  ;  while  Wrangel  "  was  watching  the 
different  turns  compass  in  hand  and  trying  to  reason  the 
true  route,  the  nati.v.  had  always  a  perfect  knowledge  of  it 
instinctively."  Moreover,  the  power  in  migratory  animals  of 
keeping  their  course  is  not  unerring,  as  may  be  inferred  from 

•  See  E.  p.  Thompson  on  the  Passions  of  Animalt,  1851,  p.  9;  and 
Alison's  remarks  on  this  head  in  the  Cyclopadia  of  Anatomy  and  Physiology, 
article  "  Instinct,"  p.  23. 

t  [I  cannot  refrain  from  ."rawing  attention  to  the  superiority  of  scientific 
metliod  and  phik)sopliical  caution  here  displayed  as  contrasted  with  Frof-jssor 
HsBckel's  views  on  tlie  same  subject,  which  in  piesenee  of  this  difHculty  at  once 
conclude  in  favour  of  som  ■  r.  .vs'terious  additional  sense  (see  p.  95). — Q-.  J.  R.] 

X  W^rangeVs  Trawls,  Ent;.  trans.,  p.  146.  See  also  Sir  G-.  Grey's  I^xpe- 
dition  to  Australia,  \oi.  i.i,  p.  72,  for  interesting  account  of  the  powers  of 
the  Australians  in  thj  SFUio  respect.  The  old  French  missionaries  used  to 
believe  that  the  N.  Anierioan  Indians  were  actually  guided  by  instinct  in 
finding  thtuc  way. 
16 


3^8 


MENTAL  EVOLUTION  IN  ANIMALS. 


the  numbers  of  lost  swallows  often  met  with  by  ships  in  the 
Atlantic :  the  migratory  salmon,  also,  often  fails  in  returning 
to  its  own  river,  "  many  Tweed  salmon  being  found  in  the 
Forth."  But  how  a  small  and  tender  bird  coming  from 
Africa  or  Spain,  after  traversing  the  sea,  finds  the  very  same 
hedge-row  in  the  middle  of  England,  where  it  made  its 
nest  last  season,  is  truly  marvellous.* 

Let  us  now  turn  to  our  domesticated  animals.     Many 
cases  are  on  record  of  animals  finding  their  way  home  in  a 
mysterious  manner,  and  it  is  asserted  that  Highland  sheep 
have  actually  swum  o^er  the  Frith  of  Forth  to  their  home  a 
hundred  miles  distant  ;t  when  bred  for  three  or  four  genera- 
tions in  the  lowlands,  they  retain  their  restless  disposition.    I 
know  of  no  reason  to  doubt  the  minute  account  given  by 
Hogg  of  a  family  of  sheep  which  bad  a  hereditary  'propensity 
to  return  at  the  breeding  season  to  a  place  ten  miles  off', 
whence  the  first  of  the  lot  had  been  brought ;  and,  after  their 
lambs  were  old  enough,  they  returned  by  themselves  to  the 
place  where  they  usually  lived :  so  troublesome  was  this  in- 
herited propensity,  associated  with  the  pe-iod  of  parturition, 
that  the  owner  was  compelled  to  sell  the  lot.f     Still  more 
interesting  is  the  account  given  by  several  authors  of  certain 
sheep  in  Spain,  which  from  ancient  times  have  annually 
migrated  during  May  from  one  part  of  the  country  to  another 
distant  four  hundred  miles :  all  the  autliors§  agree  that  "  as 
soon  as  April  comes  the  sheep  express,  by  curious  uneasy 
motions,  a  strong  desire  to  return  to  their  summer  habita- 


i  f 


•  The  number  of  birds  which  by  chauce  visit  the  Azores  (Consul  C.  Hunt, 
in  Journ.  Qeograph.  Soc,  vol.  xv,  Pt.  2,  p.  282),  so  distimt  from  Europe,  is 
probably  in  part  due  to  lost  directions  during  migration :  W.  Thompson 
{Nat.  Hist,  of  Ireland,  "  Birds,"  vol.  ii,  p.  172)  shows  that  N.  American  birds, 
which  occasionally  wander  to  Ireland,  generally  arrive  at  tlie  period  when 
they  are  migrating  in  N.  America.  In  regard  to  Salmon,  see  Scope's  Days 
of  Salmon  Fishing,  p.  47. 

+  Gardener's  Chronicle,  185^  p.  798  :  other  cases  are  given  by  Youatt  on 
Sheep,  p.  377. 

X  Quoted  by  Touatt  in  Veterinary  Journal,  vol.  t,  p.  282. 

§  Bourgoanne's  Travels  in  Spain  (Eng.  trans.),  1789,  vol.  i,  pp.  38-54. 
In  Mills'  Treatise  on  Cattle,  177  »,  p.  342,  there  is  an  extract  of  a  letter  from 
a  gentleman  in  Spain  from  which  I  have  made  extract.  Youatt  on  the  Sheep, 
p.  153,  gives  references  to  three  other  publications  with  similar  accounts.  I 
may  add  that  von  Tschudi  {Sketches  of  Nature  in  the  Alps,  Eng.  trans., 
1856,  p.  160)  states  that  annually  in  the  spring  the  cattle  are  greatly  excited, 
when  they  hear  the  great  bell  which  is  carried  with  them  ;  W(>11  knowing  that 
this  ia  the  signal  for  their  "  approaching  migration  "  to  the  higher  Alps. 


APPENDIX. 


359 


in  the 
:  from 


tions."  "  The  unquietude,"  says^nother  author,  "  which  they 
manifest  might  in  case  of  need  serve  as  an  almanack."  "  The 
shepherds  must  then  exert  all  their  vigilance  to  prevent  them 
escaping,"  "  for  it  is  a  known  truth  that  they  would  go  to  the 
very  pface  where  they  had  been  born."  Many  cases  have 
occurred  of  three  or  four  sheep  having  started  and  performed 
the  journey  by  themselves,  though  generally  these  wanderers 
are  destroyed  by  the  wolves.  It  is  very  doubtful  whether 
these  migratory  sheep  are  aborigines  of  the  country ;  and  it 
is  certain  that  within  a  comparatively  recent  period  their 
migrations  have  been  widely  extended :  this  being  the  case,  I 
think  there  can  hardly  be  a  doubt  that  this  "  natural  instinct," 
as  one  author  calls  it,  to  migrate  at  one  particular  season  in 
one  direction  has  been  acquired  during  domestication,  based 
no  doubt  on  that  passionate  desire  to  return  to  their  birth- 
place which,  as  we  have  seen,  is  common  to  many  breeds  of 
sheep.  The  whole  case  seems  to  me  strictly  parallel  to  the 
migrations  of  wild  animals. 

Let  us  now  consider  how  the  more  remarkable  migrations 
could  possibly  have  originated.  Take  the  case  of  a  bird  being 
driven  each  year,  by  cold  or  want  of  food,  slowly  to  travel 
northward,  as  is  the  case  with  some  birds ;  and  in  time  we 
may  well  believe  that  this  compulsory  travelling  would 
become  an  instinctive  passion,  as  with  the  sheep  in  Sr  ^in. 
Now  during  the  long  course  of  ages,  let  valleys  become  con- 
verted into  estuaries,  and  then  into  wider  and  wider  arms  of 
the  sea ;  and  still  I  can  well  believe  that  the  impulse  which 
leads  the  pinioned  goose  to  scramble  northward  would  lead 
our  bird  over  the  trackless  waters ;  and  that,  by  the  aid  of 
the  unknown  power  by  which  mmy  animals  (and  savage 
men)  can  retain  a  true  course,  it  would  safely  cross  the 
sea  now  covering  the  submerged  path  of  its  ancient  land 
journey.* 

•  I  do  not  suppose  that  the  line  of  migration  of  birds  always  marks  the 
line  of  formerly  continuous  land.  It  is  possible  that  a  bird  accidentally 
blown  to  a  distant  land  or  island,  after  staying  some  time  and  breedmg  there, 
might  be  induced  by  its  innate  instinct  to  lly  away,  and  agam  to  return  there 
in  the  breeding  season.  But  I  know  of  no  facts  to  coimtenance  the  idea ; 
and  I  have  been  much  struck  in  the  case  of  oceanic  islands,  lyu  ,3  at  no  ex- 
cessive distance  from  the  mainland,  but  which  from  reasons  to  be  given  in  a 
future  chapter  I  do  not  believe  have  ever  been  joined  to  the  mainland,  with 
the  fact  that  thev  seem  most  rarely  to  have  any  migratory  birds.  Mr.  E  V. 
Hnrcourt  who  has  written  on  the  birds  of  Madeira,  i.-iornis  rae  that  there 
are  none 'in  that  island;  bo.  I  am  informed  by  Air.  Caiow  Hunt,  it  is  m  th* 


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MENTAL  EVOLUTION  IN  ANIMALS. 


[I  will  give  one  case  of  migration  which  seemed  to  me  at 
first  to  offer  especial  difficulty.  It  is  asserted  that  in  the 
extreme  north  of  America,  Elk  and  Eeindeer  annually  cross,  as 
if  they  could  smell  the  herbage  at  the  distance  of  a  hundred 
miles,  a  tract  of  absolute  desert,  to  visit  certain  islands  where 
there  is  a  better  (but  still  scanty)  supply  of  food.  How 
could  their  migration  have  been  iirst  established  ?  If  the 
climate  formerly  had  been  a  little  more  favourat  le,  the  desert 
a  hundred  miles  in  width  might  then  have  been  clothed  with 
vegetation  sufficient  to  have  just  tempted  the  quadrupeds 
over  it,  and  so  to  have  found  out  the  more  fertile  northern 
islet.  But  the  intense  Glacial  preceded  our  present  climate, 
and  therefore  the  idea  of  a  former  better  climate  seemed  quite 
untenable;  but  if  those  American  geologists  are  right  who 
believe,  from  the  range  of  recent  shells,  that  subsequently  to 
the  Glacial  period  there  was  one  slightly  warmer  than  the 
present  period,  then  perhaps  we  have  a  key  to  the  migration 
across  the  desert  of  the  Elk  and  lieindeer.*] 

Instinctive  Fear. — I  have  already  discussed  the  hereditary 
tameness  of  our  domestic  animals ;  from  what  follows  I  have 
no  doubt  that  the  fear  of  man  has  always  iirst  to  be  acquired 
in  a  state  of  nature,  and  that  under  domestication  it  is  merely 
lost.  In  all  iij3  few  archipelagoes  and  islands  inhabited  by 
man,  of  which  I  have  been  able  to  find  an  early  account,  the 
native  animals  were  entirely  void  of  fear  of  man :  I  have 
ascertained  this  in  six  cases  in  the  most  distant-parts  of  the 
world,  and  with  birds  and  mammals  of  the  most  different 
kinds.f     At  the  Galapagos  Islands  I  pushed  a  hawk  off  a 

Azores,  though  he  thinks  that  perhaps  the  Quail,  which  migrates  from 
island  to  island,  may  leave  the  Archipelago.  [In  pencil  it  is  added  "  Canaries 
none."— G.  J.  R.] 

In  the  Falkland  Islands,  bo  far  as  I  can  find,  no  land-bird  io  migratory. 
From  enquiries  which  I  have  made,  I  find  there  is  no  migratory  bird  in 
Mauritius  or  Bourbon.  Colenso  asserts  {Tasmanian  Journal,  vol.  ii,  p.  227) 
that  a  cuckoo,  C.  lucidus,  is  migratoiy,  remaining  only  three  or  four  months 
in  New  Zealand ;  but  New  Zealand  is  so  large  an  island  that  it  may  very 
easily  migrate  to  the  south  and  remain  there  quite  unknown  to  the  natives  of 
the  north.  Faroe,  situated  about  180  miles  from  the  north  of  Scotland,  have 
several  migratory  birds  (Graber,  Tagebuch,  1830,  s.  205)  j  Iceland  seems  to 
be  the  strongest  exception  to  the  general  rule,  but  it  lies  only  miles 

from  the  line  of  100  fathoms.     [The  last  ten  words  are  added 

in  pencil  with  the  blanks  left  for  subsequent  filling  in. — G.  J.  R.] 

*  [The  paragraph  which  I  have  enclosed  in  square  brackets  is  faintly 
rtruck  out  in  pencil. — G.  J.  R.]. 

t  I  have  given  in  my  Journal  of  Researches  (1845),  p.  378,  details  on  th» 
Falkland  and  Galapagos.    Mr.  Cada  Mosto  (Kerr's  Collection  of  Votfagea^ 


i 


! 


APPENDIX. 


361 


tree  with  the  muzzle  of  my  gun,  and  the  little  birds  drank 
water  out  of  a  vessel  which  I  held  in  my  hand.  But  I  have 
in  my  "Journal"  given  details  on  this  subject,  and  I  will 
here  only  remark  that  the  tameness  is  not  general,  but  special 
towards  man ;  for  at  the  Falklands  the  geese  build  on  the 
outlying  islands  on  account  of  the  foxes.  These  wolf-like 
foxes  were  here  aa  fearless  of  man  as  were  the  birds,  and  the 
sailors  in  Byron's  voyage,  mistaking  their  curiosity  for  fierce- 
ness, ran  into  the  water  to  avoid  them.  In  all  old  civilized 
countries  the  wariness  and  fear  of  even  young  foxes  and 
wolves  are  well  known.*  At  the  Galapagos  Islands  the  great 
land  lizards  {Amllyrhynchus)  were  extremely  tame,  so  that  I 
could  pull  them  by  the  tail ;  whereas  in  other  parts  of  the 
world  large  lizards  are  wary  enough.  The  aquatic  lizard  of 
the  same  genus  lives  on  the  coast,  is  adapted  to  swim  and 
dive  perfectly,  and  feeds  on  submerged  algse:  no  doubt  it 
must  be  exposed  to  danger  from  the  sharks,  and  consequently, 
though  quite  tame  on  the  land,  I  could  not  drive  them  into 
the  water,  and  when  I  threw  them  in  they  always  swam 
directly  back  to  the  shore.  See  what  a  contrast  with  all 
amphibious  animals  in  Europe,  which  when  disturbed  by  the 
most  dangerous  animal,  man,  instinctively  and  instantly  take 
to  the  water. 

The  tameness  of  the  birds  at  the  Falklands  is  particularly 
interesting,  because  most  of  the  very  same  species,  more  espe- 
cially the  larger  birds,  are  excessively  wild  in  Tierra  del 
Fuego,  where  for  generations  they  have  been  persecuted  by 
the  savages.  Both  at  these  islands  and  at  the  Galapagos  it 
is  particularly  noteworthy,  as  I  have  shown  in  my  "  Journal" 
by  the  comparison  of  the  several  accounts  up  to  the  time 
when  we  visited  these  islands,  that  the  birds  are  gradually 
getting  less  and  less  tame ;  and  it  is  surprising,  considering 
the  degree  of  persecution  which  they  have  occasionally  suf- 

▼ol.  ii,  p.  246)  says  that  at  the  C.  de  Verde  Islands  the  pigeons  were  so  tame 
ae  readily  to  be  caught.  These,  then,  are  the  only  large  groups  of  islands, 
with  the  exception  of  the  oceanic  (of  which  I  can  find  no  early  account) 
which  were  uninhabited  when  discovered.  Thos.  Herbert  in  1626  in  his 
Travels  (p.  349)  describes  the  tameness  of  the  birds  at  Maiiritius,  and  Du 
Bois  in  1669-72  enters  into  details  on  this  head  with  respect  to  all  the  birds 
at  Bourbon.  Capt.  Moresby  lent  me  a  M3  account  of  his  survey  of  St.  Pierre 
and  Providence  Islands,  north  of  Madagascar,  in  which  he  describes  the 
extreme  tameness  of  the  pigeons.  Capt.  Cannichael  has  described  th*  tame- 
ness of  the  birds  at  Tristan  d'Acunha. 
•  lie  Roy,  Lettres  i'hiloso^h.,  p.  86. 


hi 


m 


iH'L  .. 


362 


MENTAL  EVOLUTION  IN  ANIMALS 


fered  during  the  last  one  or  two  centuries,  that  they  havn  not 
become  wilder;  it  shows  that  the  fear  of  man  is  not  soon 
acquired. 

In  old  inhabited  countries,  where    the    animals    have 
acquired  much  general  and  instinctive  suspicion  and  fear, 
they  seem  very  soon  to  learn  from  each  other,  and  perhaps 
even  from  other  species,  caution  directed  towards  any  par- 
ticular object.    It  is  notorious  that  rats  and  mire  cannot  long 
be  caught  by  the  same  sort  of  trap,*  however  tempting  the 
bait  may  be;  yet,  as  it  is  raiv  that  one  which  has  actually 
been  caught  escapes,  the  others  must  have  learnt  the  danger 
from  seeing  their  companions  suffer.     Even  the  most  terrffic 
object,  if  never  causing  danger,    and  if   not   insiiTictively 
dreaded,  is  immediately  viewed  with  indifference,  as  we  see  ia 
our  railway  trains.    What  bird  is  so  difficult  to  approach  as 
the  heron,  and  how  many  generations  would  it  not  require  to 
make  herons  fearless  of  man  ?    Yet  Mr.  Thompson  saysf  that 
these  birds,  after  a  few  days'  experience,  would  fearlessly 
allow  a  train  to  pass  within  half  gun-shot  distance.|  Although 
It  cannot  be  doubted  that  the  fear  of  man  in  old  inhabited 
countries  is  partly  acquired,  yet  it  also  certainly  is  instinc- 
tive ;  for  nesting  birds  are  generally  terrified  at  the  first  sight 
of  man,  and  certainly  far  more  so  than  most  of  the  old  birds 
at  the  Falklands  and  Galapagos  Archipelago  after  years  of 
persecution. 

We  have  in  England  excellent  evidence  of  the  fear  of 
man  being  acquired  and  inherited  in  proportion  to  the  danger 
incurred ;  for,  as  was  long  ago  remarked  by  the  Hon.  Daines 
Barnugton,§  all  our  large  birds,  young  and  old,  are  extremely 
wild.     Yet  there  can  be  no  relation  between  size  and  fear; 

*  E.  P.  Thompson,  Passions  of  Animals,  p.  29. 

t  JSTat.  Hist,  of  Ireland,  "  Birds,"  vol.  ii,  p.  133. 

t  [I  may  here  refer  to  the  corroboration  which  this  staVement  has 
recently  received  in  a  correspondence  between  Dr.  Rau  and  JV/r  Goodsir 
{^(^ture,  July  3rd,  12th,  and  19th,  1883).  The  former  says  that  the  wild 
duck,  teal,  &c.,  which  frequent  certain  districts  through  which  'he  Pacific 
Kailway  has  been  carried  in  Canada,  became  quite  fearless  of  the  bmins  the 
tirst  tew  days  after  traffic  was  opened,  and  the  latter  gives  similar  testimony 
concerning  the  'w-ild  fowl  of  Australia,  adding,  «  The  constant  roar  of  a 
great  passing  traffic,  as  well  as  the  unceasing  turmoil  and  unearthly  noises  of 
a  large  railway  station  withm  a  stone's  throw  of  their  haunfs,  is  now  quite 
unnoticed  by  these  usually  most  watchful  and  wary  of  all  birds,  [i.e.,  wild 
ducks.]  But  for  fear  of  trespassing  on  your  space,  I  could  give  many 'more 
xliu^ifcrations  of  the  truth  of  Dr.  Rae'a  remarks."— Q-  JET 

§  Phil.  Trans.,  1773,  p.  264. 


hi 


APPENDIX. 


363 


for  on  unfrequented  islands,  when  first  visited,  the  large 
birds  were  as  tame  as  the  small.  How  exceedingly  wary  is 
our  magpie ;  yet  it  fears  not  horses  or  cows,  and  sometimes 
alights  on  their  backs,  just  like  the  doves  at  the  Galapagos 
did  in  1G84  on  Cowley.  In  Norway,  where  the  magpie  is 
not  persecuted,  it  picks  up  food  "close  about  the  doors, 
sometimes  walking  inside  the  houses."*  The  hooded  crow 
(C.  comix),  again,  is  one  of  our  wildest  birds ;  yet  in  Egypti 
is  perfectly  tarn  Every  single  young  magpie  and  crow 
cannot  have  beeu  i  ightened  in  P^ngland,  and  yet  all  are 
fearful  of  man  in  the  extreme:  on  the  other  hand,  in  the 
Falkland  and  Galapagos  Islands  many  old  birds,  and  their 
parents  before  them,  must  have  been  frightened  and  seen 
others  killed ;  yet  they  have  not  acquired  a  salutary  dread  of 
the  mc^t  destructive  animal,  man.t 

Animals  feigning,  as  it  is  said.  Death— an  unknown  state 
to  each  living  creature — seemed  to  me  a  remarkable  instinct. 
I  agree  with  those  authors  §  who  think  that  there  has  been 
much  exaggeration  on  this  subject:  I  do  not  doubt  that 
fainting  (I  have  had  a  Eobin  faint  in  my  hands)  and  the 
paralyzing  effects  of  excessive  fear  have  sometimes  been  mis- 
taken for  the  simulation  of  death.||     Insects  are  most  notori- 

•  Mr.  C.  Hewitson  in  Magazine  of  Zoology  and  Botany,  vol.  ii,  p.  311. 

t  Gcotfry  St.  Hilaire,  Amis,  des  Mus.,  tome  ix,  p.  471. 

X  [I  have  already  pointed  out  the  refined  degree  to  which  snch  instinctive 
dread  of  man  is  developed  when  it  is  able  accurately  to  discriminate  what 
constitutes  safe  distance  from  fire-arms.  Since  writing  the. passage  to  which 
I  allude  (see  p.  11*7),  I  have  met  with  the  following  observation  in  the  letters 
recently  published  by  Dr.  Kae  in  Nature,  which  is  of  interest  as  showing  how 
rapidly  such  refinement  of  discrimination  is  attained:—"  I  may  perhaps  be 
permitted  to  give  one  of  many  instances  known  to  me  of  the  quickness  of 
birds  in  acquiring  a  knowledge  of  danger.  Golden  plover,  when  coming  from 
their  breeding-places  in  high  latitudes,  visit  the  islands  north  of  Scotland  in 
large  numbers,  and  keep  together  in  great  packs.  At  first  they  are  easily 
approached,  but  after  a  very  few  shots  being  fired  at  them,  they  become  not 
only  much  more  shy,  but  seem  to  measure  with  great  accuracy  the  distance 
at  which  they  are  sate  from  harm."— G-.  J.  R.] 

§  Couch,  Illustrations  of  Instinct,  p.  201. 

II  The  most  curious  case  of  apparently  true  simulation  of  death  is  that 
given  by  Wrangel  {Travels  in  Siberia,  p.  312,  Eng.  trans.)  of  the  geese  which 
migrate  to  the  Tundras  to  moult,  and  are  then  quite  incapable  of  flight.  He 
savs  they  feigned  death  so  well  "with  their  legs  and  necks  stretched  out 
quite  stiff,  that  I  passed  them  by,  thinking  they  were  dead."  But  the  natives 
were  not  thus  taken  ifl.  This  simulation  would  not  save  them  from  foxes  or 
wolves,  &c.,  which  I  presume  inhabit  the  Tundras  :  would  it  save  them  from 
hawks  P  The  case  seema  a  strange  one.  A  lizard  in  Patagonia  {Journal  of 
Researches,  p.  97),  which  lives  on  the  sand  near  the  coast,  and  is  speckled 
like  it,  when  frightened  feigned  death  with  outstretched  legs,  depressed  body. 


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ous  m  this  respect.    We  have  amongst  them  a  most  perfect 

Sir'^T.'i^'''  ^^%  TT  ^"""«  (^'  I  h^ve  observed  iA 
l^urculio  and  Chrysomela),  from  species  which  feign  only  for 
a  second  and    sometimes  imperfectly,  still  moving    their 
antenn^(aswith  some  Histers),  and  which  wiU  not  fei-n  a 
second  time  however  much  irritated,  to  other  species  which 
according  to  De  Geer,  may  be  cruelly  roasted  at  a  slow  fire.' 
without  the  slightest  movement^to  others,  again,  which  will 
long  remain  motionless  as  much  as  twenty-three  minutes,  as  I 
nnd  with  Chrysomela  spartii.     Some  individuals  of  the  same 
species  of  Ptinus  assumed  a  different  position  from  that  of 
others   Now  it  will  not  be  disputed  that  the  manner  and  dura- 
tion  of  the  feint  is  useful  to  each  species,  according  to  the  kind 
of  danger  which  it  has  to  escape ;  therefore  ther?  is  no  more 
real  difficulty  m  its  acquirement,  through  natural  selection, 
of  this  hereditary  attitude  than  of  any  other.    Nevertheless 
It  struck  me  as  a  strange  coincidence  that  the  insects  should 
thus  have  come  to  exactly  simulate  the  state  which  they  took 
when  dead.    Hence  I  carefully  noted  the  simulated  positions 
of  seventeen  different  kinds  of  insects  (including  an  lulus 
bpider,  and  Oniscus)  belonging  to  the  most  distinct  genera" 
both  poor  and  first-rate  shammers;  afterwards  I  procured 
naturally  dead  specimens  of  some  of  these  insects,  others  I 
killed  with  camphor  by  an  easy  slow  death;  the  result  was 
tfiatmno  one  mstance  was  the  attitude  exactly  the  same 
and  m  several  instances  the  attitude  of  the  feigners  and  of 
the  really  dead  were  as  unlike  as  they  possibly  could  be. 

Nidificahon  and  HaUtation.~WQ  come  now  to  more 
complex  instincts.  The  nests  of  Birds  have  been  carefully 
attended  to,  at  least  m  Europe  and  the  United  States ;  so 
that  we  have  a  good  and  rare  opportunity  of  seeing  whether 
TT.l^.^^l  ^?"^^^on  i^  an  important  instinct,  and  we  shall 
find  that  this  is  the  case.  We  shall  further  find  that  favour- 
able opportunities  and  intelligence  sometimes  slightly  modify 
the  constructive  instinct  In  the  nests  of  birds,  also,  we 
have  an  unusually  perfect  series,  from  those  which  build 
none,  but  lay  on  the  bare  ground,  to  others  which  make  a 
most  imperfect  and  simple  nest,  to  others  more  perfect,  and 

Sna^'lTh '  ^  ^"^^n  ^'^\^'  it  buried  itself  quickly  in  the  sand.  If 
lllr^r^  *^'^°  V™?]^  insignificant  animal,  and  if  she  hid  closed  her  48 
death?     ^''^''^.'f^T^^  ^^  "°*  P«"^^P«  h^^«  «aid  that  she  was  feigning 


APPENDIX. 


365 


st  perfect 
served  in 
1  only  for 
ng    their 
)t  feign  a 
es  which, 
slow  fire, 
hich  will 
utes,  as  I 
the  same 
1  that  of 
nd  dura- 
the  kind 
no  more 
selection, 
jrtheless, 
s  should 
'hey  took 
positions 
n  lulus- 
;  genera, 
procured 
others  I 
suit  was 
le  same, 
3  and  of 
.  be. 

to  more 
larefully 
ates;  so 
whether 
we  shall 
favour- 
modify 
ilso,  we 
h  build 
make  a 
3ct,  and 

sand.     If 

i  her  ..yea 

I  feigning 

to  Ento- 


BO  on,  till  we  arrive  at  marvellous  structures,  rivalling  the 
weavers'  art. 

Even  in  so  singular  a  nest  as  that  of  the  Hirundo  ICoU 
loeaha  esculenta),  eaten  by  the  Chinese,  we  can,  I  think,  trace 
the  stages  by  which  the  necessary  instinct  has  been  acquired. 
The  nest  is  composed  of  a  brittle  white  translucent  substance 
very  like  pure  gum  arabic,  or  even  glass,  lined  with  adherent 
feather-down.  The  nest  of  an  allied  species  in  the  British 
Museum  consists  of  irregularly  reticulated  fibres,  some  as 
fine  as  *  of  the  same  substance  ;  in  another  species 

bits  of  sea-weed  are  agglutinated  together  with  a  similar 
substance.  This  dry  mucilaginous  matter  soon  absorbs 
water  and  softens  :  examined  under  the  microscope  it 
exhibits  no  structure,  except  traces  of  lamination,  and  very 
generally  pear-shaped  bubbles  of  various  sizes  ;  these,  indeed, 
are  very  conspicuous  in  small  dry  fragments,  and  some  bits 
looked  almost  like  vesicular  lava.  A  small  pure  piece  put 
into  flame  crackles,  swells,  does  not  readily  burn,  and  smells 
strongly  of  animal  matter.  The  genus  Collocalia,  according 
to  Mr.  G.  E.  Gray,  to  whom  I  am  much  obliged  for  allowing 
rae  to  examine  all  the  specimens  in  the  British  MuseunT, 
ranks  in  the  same  sub-family  with  our  common  Swift.  The 
latter  bird  generally  seizes  on  the  nest  of  a  sparrow,  but  Mr. 
Macgillivray  has  carefully  described  two  nests  in  which 
the  confusedly  fitted  materials  were  agglutinated  together 
by  extremely  thin  shreds  of  a  substance  which  crackles 
but  does  not  readily  burn  when  put  into  a  flame.  In 
N.  Americaf  another  species  of  Swift  causes  its  nest  to 
adhere  against  the  vertical  wall  of  a  chimney,  and  builds  it 
of  small  sticks  placed   parallel   and  agglutinated  together 

•  [In  the  MS  a  blank  is  here  intentionally  left  for  the  subsequent  fiUine 
in  or  an  appropriate  word. — G.  J.  R,]  ° 

/e'^%^"^^**^''*  >nMran««  see  Macgillivray,  British  Birds,  vol.  iii,  1840 
p.  625.     For  C.  pelaxgius,  see  Mr.  Peabody's  excellent  paper  on  the  Birds  of 
Massachussetts  in  the  Boston  Journal  of  Nat.  Hist.,  vol.  iii,  p.  187.     M    E 
Robert  (Com/)^e«  Rendus,  quoted  in  Anns,  and  Mag.  of  Nat.  HUt.,  \ol  viii 
^^^^>  V-^'^^)  fo'ind  that  the  nests  of  the  Hirundo  riparia,  made  in  the 
gravelly  banks  of  the  Volga,  had  their  upper  surfaces  plastered  with  a  yellow 
animal  substance,  which  he  imagined  to  be  fishes'  spawn.    Could  he  have 
mistaken  the  species,  for  there  is  no  reason  to  suppose  our  bank-martin  has 
any  such  habit?     This  would  be  a  very  remarkable  variation  of  instinct,  if  it 
could  be  proved;  and  the  more  remarkable  that  this  bird  belongs  t^  a  dif- 
ferent  sub-family  from  the  Swifts  and  Collocalia.     Yet  I   am  inclined  to 
believe  it,  for  it  has  been  affinned  with  apparent  truth  that  the  House-martin 
moistens  the  mud,  with  which  it  builds  its  nest,  with  adhesive  saliva. 
24 


363 


MENTAL  EVOLUTION  IN  ANIMALS. 


with  cakes  of  a  brittle  mucilage  which,  like  that  of  the 
esculent  swallow,  swells  and  softens  in  water ;  in  flame  it 
crackles,  swells,  does  not  readily  burn,  and  emits  a  strong 
animal  odour :  it  differs  only  in  being  yellowish-brown,  in  not 
having  so  many  large  air-bubbles,  in  being  more  plainly 
laminated,  and  in  having  even  a  striated  appearance,  caused 
by  innumerable  elliptical  excessively  minute  points,  which  I 
believe  to  be  drawn-out  minute  air-bubbles. 

Most  authors  believe  that  the  nest  of  the  esculent  swallow 
is  formed  of  either  a  Fucus  or  of  the  roe  of  a  fish ;  others,  I 
believe,  have  suspected  that  it  is  formed  of  a  secretion  from 
the  salivary  glands  of  the  bird.  The  latter  view  I  cannot 
doubt,  from  the  preceding  observations,  is  the  correct  one. 
The  inland  habits  of  the  Swifts  and  the  manner  in  which  the 
substance  behaves  in  flame  almost  disposes  of  the  supposition 
of  Fucus.  Nor  can  I  believe,  after  having  examined  the 
dried  roe  of  fishes,  that  we  should  find  no  trace  of  cellular 
matter  in  the  nests,  had  they  been  thus  formed.  How  could 
our  Swifts,  the  habits  of  which  are  so  well  known,  obtain  roe 
without  being  detected  ?  Mr.  Macgillivray  has  shown  that 
the  salivary  crypts  of  the  Swifts  are  largely  developed,  and 
he  believes  that  the  substance  with  which  the  materials  of  its 
nest  are  fitted  together,  is  secreted  by  their  glands.  I  cannot 
donbt  that  this  is  the  origin  of  the  similar  and  more  copious 
substance  in  the  nest  of  the  North  American  Swift,  and  in 
those  of  the  Collocalia  escuhnta.  We  can  thus  understand 
its  vesicular  and  laminated  structure,  and  the  curious  reti- 
culated structure  of  the  Philippian  Island  species.  The  only 
change  required  in  the  instinct  of  these  several  birds  is  that 
less  and  less  foreign  materials  should  be  used.  Hence  I  con- 
clude that  the  Chinese  make  soup  of  dried  saliva.* 

In  looking  for  a  perfect  series  in  the  less  common  forma 
of  birds'  nests,  we  should  never  forget  that  all  existing  birds 
must  be  almost  infinitely  few  compared  with  those  which 
have  existed  since  footprints  were  impressed  on  the  beach  of 
the  New  Eed  Sandstone  formation  of  North  America. 

If  it  be  admitted  that  the  nest  of  each  bird,  wherever 
placed  and  however  constructed,  be  good  for  that  species 

*  [It  is  almost  needless  to  observe  that  we  must  remember  the  date  at 
which  this  was  written ;  but  it  may  be  remarked  that  as  early  as  1817  it  was 
pointed  out  by  Home  {Phil.  Trans.,  p.  332)  that  the  proventriculus  of  Collo- 
calia is  a  peculiar  glandular  structure  probably  suited  to  secrete  the  subatanca 
of  which  the  nest  consists. — Q-.  J.  R.] 


APPENDIX. 


367 


strong 


under  its  own  conditions  of  life ;  and  if  the  nesting-instinct 
varies  ever  so  little,  when  a  bird  is  placed  under  new  con- 
ditions, and  the  variations  can  be  inherited,  of  which  there 
can  be  little  doubt— then  natural  selection  in  the  course  of 
ages  might  modify  and  perfect  almost  to  any  degree  the  nest 
of  a  bird  in  comparison  with  that  of  its  progenitors  in  lon» 
past  ages.     Let  me  take  one  of  the  most  extraordinary  cases 
on  record,  and  see  how  selection  may  possibly  have  acted  •  I 
refer  to  Mr.  Gould's  observation*  on  the  Australian  Me^a- 
podidse.      The   Talegalla  lathami  scrapes  together  a  great 
pyramid,  from  two  to  four  cart-loads  in  amount,  of  decayin^y 
vegetable  matter ;  and  in  the  middle  it  deposit  its  eggs.     The 
eggs  are  hatched  by  the  fermenting  mass,  the  heat  of  which 
was  estimated  at  90°  F.,  and  the  young  birds  scratch  their 
way  out  of  the  mound.     The  accumulation  propensity  is  so 
strong  that  a  single  unmated  cock  confined  in  Sydney  annually 
collected  an  immense  mass  of  vegetable  matter.     The  Leipoa 
ocellata  makes  a  pile  forty-five  feet  in  circumference  and  four 
feet  in  height,  of  leaves  thickly  covered  with  sand,  and  in 
the  same  way  leaves  its  - 'j^gs  to  be  hatched  by  the  heat  of 
fermentation.       The  Megapodius  tumulus  in  the  northern 
parts  of  Australia  makes  even  a  much  larger  mound   but 
apparently  including  less  vegetable  matter;  and  other  species 
in  the  Mflayan  Archipelago  are  said  to  place  their  eg^s  in 
holes  in  the  ground,  where  they  are  hatched  by  the  heat  of 
the  sun  alone.     It  is  not  so  surprising  that  these  birds  should 
have  lost  the  instinct  of  incubation,  when  the  proper  tem- 
perature is  supplied  either  from  fermentation  or  the  sun  as 
that  they  should  have  been  led  to  pile  up  beforehand  a  great 
heap  of  vegetable  matter  in  order  that  it  might  ferment  • 
for,  however  the  fact  may  be  explained,  it  ig  known  that 
other  birds  wHl  leave  their  eggs  when  the  heat  is  sufficient 
for  incubation,  as  in  the  case  of  the  Fly-catcher  which  built 
Its  nest  in  Mr.  Knight's  hot-house.f    Even  the  snake  takes 
advantage  of  a  hot-bed  in  which  to  lay  its  eggs ;  and  what 
concerns  us  more,  is  that  a  common  hen,  according  to  Pro- 
fessor Fischer,  "made  use  of  the  artificial  heat  of  a  hot-bed  to 
hatch  her   eggs."  J     Again  Eeaumur,  as  well   as   Bonnet, 

*  Birds  of  Australia,  and  Introduction  to  the  Birds  of  Australia  1848 
p.  82.  '  * 

+  YarreVs  British  Birds,  vol.  i,  p.  166. 

^:  Alison,  article  "Instinct"  in  Todd',  Cyclop,  of  Anat.  and  Physiol.^ 


'  1   I 


lii 


II  i 


368 


MENTAL  EVOLUTION  IN  ANIMALS. 


observed*  that  ants   ceased  their  laborious  task  of  daily 
n     moving  their  eggs  to  and  from  the  surface  according  to  the 
/     heat  of  the  sun,  when  they  had  built  their  nest  between  the 
two  cases  of  a  bee-hive,  where  a  proper  and  equable  tempe- 
rature was  provided. 

Now  let  us  suppose  that  the  conditions  of  life  favoured 
the  extension  of  a  bird  of  this  Family,  whose  eggs  were 
hatched  by  the  solar  rays  alone,  into  a  cooler,  damper,  and 
more  wooded  country :  then  those  individuals  which  chanced  to 
have  the  accumulative  propensity  so  far  modified  as  to  prefer 
more  leaves  and  less  sand,  would  be  favoured  in  their  exten- 
sion ;  for  they  would  accumulate  more  vegetable  matter,  and 
its  fermentation  would  compensate  for  the  loss  of  solar  heat, 
and  thus  more  young  birds  would  be  hatched  which  might  as' 
readily  inherit  the  peculiar  accumulative  propensity  of  their 
parents  as  our  breeds  of  dogs  inherit  a  tendency  to  retrieve, 
another  to  point,  and  another  to  dash  round  its  prey.  And 
this  process  of  natural  selection  might  be  continued,  till  the 
eggs  came  to  be  hatched  exclusively  by  the  heat  of  fermen- 
tation ;  the  bird,  of  course,  being  as  ignorant  of  the  cause  of 
the  heat  as  of  that  of  its  own  body. 

In  the  case  of  corporeal  structures,  when  two  closely 
allied  species,  one  for  instance  semi-aquatic  and  the  other 
terrestrial,  are  modified  for  their  different  manners  of  life, 
their  main  and  general  agreement  of  structure  is  due,  according 
to  our  theory,  to  descent  from  common  parents ;  and  their 
slight  differences  to  subsequent  modification  through  natural 
selection.  So  when  we  hear  that  the  thrush  of  South  America 
(T.  Falklandicus),  like  our  European  species,  lines  her  nest  in 
the  same  peculiar  way  with  mud,  though,  from  being  sur- 
rounded by  wholly  different  plants  and  animals,  she  must  be 
placed  under  somewhat  different  conditions;  or  when  we 
hear  that  in  Nortn  America  the  males  of  the  kitty  wrens,t 
like  the  male  of  our  species,  have  the  strange  and  anomalous 
habit  of  making  "cock-nests,"  not  lined  with  feathers,  in 
which  to  shelter  themselves ; — when  we  hear  of  such  cases, 
and  they  are  sufficiently  numerous  in  all  classes  of  animals, 
we  must  attribute  the  similarity  of  the  instinct  to  inheritance 
from  common  progenitors,   and  the  dissimilarity,  either  to 

*  Kirby  and  Spence,  Introd.  to  Entomol.,  vol.  ii,  p.  519. 
t  Peabody  in  Boaton  Journ.  Nat.  Hist.,  vol.  iii,  p.  144.    For  our  British 
species  see  Macgillivray,  Brit.  Birds,  vol.  iii,  p.  23. 


APPENDIX, 


369 


Beected  and  profitable  modification,  or  to  acquired  and 
inherited  habit  In  the  same  manner,  as  the  northern  and 
southern  thrushes  have  largely  inherited  their  instinctive 
modihcation  from  a  common  parent,  so  no  doubt  the  thrush 
and  blackbird  have  likewise  inherited  much  from  their 
common  progenitor,  but  with  somewhat  more  considerable 
modifications  of  instinct  in  one  or  both  species,  from  that  of 
tneir  ancient  and  unknown  ancestor. 

nn  Z^kT"^  now  consider  the  variability  of  the  nesting-imtinct.  The  cases 
no  doubt,  would  hare  been  far  more  numerous,  had  the  subiect  been  attended 
Sta7e,  1L°°"S"''  with  the  same  care  as  in  Great  Britin  and  the  Sd 
States.     From  the  general  uniformity  of  the  nests  of  each  species,  we  cleaHv 

chosln  onT."?'"^  t^^'l^'  ^"l^  ^'  ''''  '"^^^^I'  "««d  aSdtfe  situation 
chosen  on  a  high  or  low  branch,  on  a  bank  or  on  level  ground,  whether 

nstnS°TheT;?"°^'T'-T  T*  ^'''  to  chance,  or  to  int'elligen'ce  but  i 
instinct  The  Sj/lvia  sylmcola,  for  instance,  can  be  distinguished  from  two 
c  o  ely  allied  wrens  more  readily  by  its  nest  being  lined  with  feathers  Zn  by 
almost  any  other  character.     ('•  Yarrell's  British  Birds  ")  ^ 

««f«  T''*^  ""^  compulsion  often  leads  birds  to  change' the  situation  of  their 
nests:  numerous  instances  could  be  given  in  various  parts  of  the  world  of 
birds  breeding  in  trees,  but  in  treeless  countries  on  the  ground  or  Tmon^st 

fnt;  fW.w^  r''*"*^  in  "Boston  Journ.  Nat.  Hist.."  vol  iv,  p  249) 
P  Sn  ll?-  wl^"^'  ''''  ^"  ''  \*  °*^  Labrador.  '<  in  consequoce  of  th?  perse- 
M  Couoh1«?i7^rf  "'''^^^r'  °°^^^>Win  trees."  instead  of  in  the  Ss. 
Mr.  Couch  ("Illustrations  of  Instinct,"  p.  218)  states  that  three  or  four 
-ThTwhVT^'  of  the  sparrow  (F.  dolesuL)  having  be  ndesLyed' 
themsSel  1°"^'."'  '^  by  mutual  agreement,  quitted  the%lace  and  seUled 
themselves  amongst  some  trees  at  a  distance-a  situation  whi-h    thoueh 

Sred  here°  wb  ""'T^'  "l^^'^  *^^^  ""''  ^^^^^  '^'>-«t«-  had  ev;r  beSe 
bnilTl  ^r!'  ^  ""^  u'^'''  nests  became  objects  of  curiosity."  The  sparrow 
hn  i?r„„-q  l^\^  ""^^1''  °°  ^'^^  branches,  in  ivy,  under  rooks'  nests,  in  th^ 
hie  martin ^..r'"^"^"''''-"'^  °^*^°  «^'^^«  °"  '^^  °*'«t  made'by  th^ 
fZff  "^  n  ,  ^-  °^»  *^'''  ^'*"'*  ^^"^^y  according  to  the  place  "  (Mon- 
tegue.  "Ornitho.  Dict.,"p.482).  The  Heron  (Macgillivray,  "Brit.  Birds"' 
vol  IV,  p.  446:  W.  Thompson,  "Nat.  Hist.  Ireland,"  vol  i  p  146)  builda 
in  trees,  on  precipitous  sea-clifPs,  and  amongst  heath  on  the  ground      In  the 

voM??Blo1n"/'^''''l''r.°'''"*  (Peabod/in  "  Boston  Journal  Nat.  ffisJ.'' 
vol.  Ill,  p.  209)  likewise  builds  in  tall  or  low  trees,  or  on  the  ground  •  and 

s^oSmLSr^r'^'^^'  "°"^^^^-  ^  -'"--^^-   -  ^-"-.   -ci 

Tnrl!?'n?««'^°'!/*^'^*'J"^^P'.^y=  ^^  ^"^^  «««°  *''at  the  Taylor-bird  in 
Ind^a  uses    artificial    thread  instead  of  weaving  it.      A  wild   Gold-finch 

and  th°en  ^T'""''''^  ■^u'''^^'  7^'  h  P"  ^2)  first  took  wool,  then  cotton, 
wm  often  h1?M°'  ^,J^^''\'5»«  Pl^ed  near  its  nest.  The  common  Robin 
will  often  build  under  sheds,  four  cases  having  been  observed  in  one  season 
at  one  place  (W.  Thompson.  "Nat.  Hist.  Irellnd."  vol.  i,  p.  14)  In  Walea 
oilfntof ?nll7^  builds  against  perpendicular  clilfs%i?-al/SvS 
!.rl«!^  if  ^"8^=^"^  against  houses;  and  this  must  have  prodigiously  in- 
creased  Its  range  and  numbers.  In  Arctic  America  in  1^2b  Hirundoluni. 
frons  (Richardson.  "  Fauna  Boreali-Amercani,"p.  331)  for  the  first  fme  bu" It 
against  houses  ;  and  the  nests,  instead  of  being  clustered  and  each  "avin^  a 
tubular  entrance,  were  built  under  the  eaves  iS  a  single  line  and  Sthout  th2 


'i  I 


it 


r  ■; 


,r  II 


ffli^t 


V  ' 


I'  (i  [., 

r  ^1  ! 


370 


MENTAL  EVOLUTION  IN  ANIMALS. 


tubular  entrnnre,  or  with  a  more  ledge.    The  date  of  a  si.nilar  change  In  the 
habits  of  H.fulva  it  also  known. 

In  all  changes,  whether  from  persecution  or  convenience,  intelligence 
must  come  into  plaj  in  some  degree.  The  Kittj-wren  (T.  vulgaris),  which 
builds  in  various  situations,  usually  makes  its  nest  to  match  witli  surrounding 
objects  (Macgillivray,  vol.  iii,  p.  21)  ;  but  this  perhaps  is  instinct.  Yet 
wlien  wehear  from  White  (Letter  14)  that  a  Willow-wren  (and  I  have  known 
0  similar  case;,  having  been  disturbed  by  being  watched,  concealed  the  orifice 
of  her  nest,  we  might  argue  that  the  case  was  one  of  intelligence.  Neither 
the  Kitty-wren  nor  Water-ouzel  ("  Mag.  of  Zool.,"  vol.  ii,  1838,  p.  429) 
invariably  build  domes  to  their  nests,  when  placed  in  sheltered  situations. 
Jesse  describes  a  Jackdaw  which  built  its  nest  on  an  inclined  surface  in  a 
turret,  and  reared  up  a  perpendicular  stack  of  sticks  ten  feet  in  height—  a 
labour  of  seventeen  days :  families  of  this  bird,  I  may  add  (White's  "Sel- 
borne,"  Letter  21),  have  been  known  regularly  to  build  in  rabbit-burrows. 
Numerous  analogous  facts  could  be  given.  The  Water-hen  (O.  cMoropus)  is 
■aid  occasionally  to  cover  her  eggs  when  she  leaves  her  nest,  but  in  one  pro- 
tccted  place  W.  Tliompson  ("  Nat.  Hist.  Ireland,"  vol.  ii,  p.  328)  says  that 
tiiis  was  never  done.  Water-hens  and  Swans,  which  build  in  or  near  tlie 
water,  will  instinctively  raise  their  nest  as  soon  as  they  perceive  the  water 
begin  to  rise  (Couch  "  Illustrations  of  Instinct,"  p.  223-6).  But  the  follow- 
ing seems  a  more  curious  case  :— Mr  Yarrell  showed  me  a  sketch  of  the  nest 
of  a  Black  Australian  Swan,  which  hud  been  built  directly  under  the  drip  of 
tiie  eaves  of  a  building  ;  and,  to  avoid  this,  male  and  female  conjointly  added 
semicircular  «  to  the  nest,  until  it  extended  close  to  the  wall, 

within  the  line  of  drip  ;  and  then  they  pushed  the  eggs  into  the  newly  added 
portion,  so  as  to  be  quite  dry.  The  Magpie  {Corvus  pica)  under  ordinary 
circumstances  builds  a  remarkable,  but  very  uniform  nest ;  in  Norway  they 
build  in  churches,  or  spouts  under  the  eaves  of  houses,  as  well  as  in  trees. 
In  a  treeless  part  of  Scotland,  a  pair  built  for  several  vcars  in  a  gooseberry 
bush,  which  they  barricaded  all  round  in  an  extraordinary  manner  with 
briars  and  thorns,  so  that  "  it  would  have  cost  a  fox  some  days'  labour  to 
have  got  in."  On  the  other  hand,  in  a  part  of  Ireland,  where  a  reward  had 
been  offered  for  each  egg  and  the  magpies  had  been  much  persecuted,  a  pair 
,  built  at  the  bottom  of  a  low  thick  hedge,  "  without  any  large  collection  of 
materials  likely  to  attract  notice."  In  Cornwall,  Mr.  Couch  says  he  hat 
seen  near  each  other,  two  nests,  one  in  a  hedge  not  a  yard  from  the  ground 
and  "  unusually  fenced  in  with  a  thick  structure  of  thorns ;"  the  other  "  on 
the  top  of  a  very  slender  and  solitary  elm— the  expectation  clearly  being 
that  no  creature  would  venture  to  climb  so  fragile  a  column."  I  have  been 
struck  by  the  slenderness  of  the  trees  sometimes  chosen  by  the  magpie  ;  but. 
int<?lligent  as  this  bird  is,  I  cannot  believe  that  it  foresees  that  boyB  could  not 
climb  such  trees,  but  rather  that,  having  chosen  such  a  tree,  it  has  found 
from  expedience  that  it  is  a  safe  place.f 

Although  I  do  not  doubt  that  intelligence  and  experience  oft«n  come 
into  play  in  the  nidification  of  Birds,  yet  both  often  fail :  a  Jackdaw  has 
been  seen  trying  in  vain  to  get  u  stick  through  a  turret  window,  and  had 


•  [A  word  is  here  accidentally  omitted  in  the  MS.— Q-.  J.  E.] 

t  For  Norway,  see  in  Mag.  of  Zool.  and  Bot.,  1838,  vol.  ii,  p.  311.    For 

Scotland,  Bev.  J.  Hall,  Travels  in  Scotland,  see  Art.  "  Instinct "  in  Cyclop. 

of  Anat.  and  Physiol,  p.  22.     For  Ireland,  W.  Thompson,  Nat.  Mist,  of 

Ireland,  vol.  ii,  p.  329.    For  Cornwall,  see  Couch,  Illustrationt  of  Imtinctt 

p.  213. 


rifi", 


APPENDIX. 


871 


not  senge  to  draw  it  in  Icngtlmays :  White  (Letter  6)  describes  some  mar- 
tins which  year  after  year  built  their  nests  on  an  exposed  wall  and  yTar  "fter 
year  thoy  were  washed  down.  The  Furnanu.  cuLulariV\TVll^Sl 
makes  a  deep  burrow  in  mud-banks  for  its  nest;  and  I  saw  r"  m^Jn? 
Researches.^.  216)  these  little  birds  vainly  burrowing  nuLrorSolel 
through  mud-waUs.  over  which  they  were  constantly  Hitting?  wKut  thus 
perceiving  that  the  walls  were  not  nearly  thick  enougfi  for  thdVTests 

Many  variations  cannot  in  any  wav  be  account prlfr... .  f  i.„  n  t 
Zan«MPeabody  "Boston  Journ^af.  His^" "oili. %;  2  9)  wTerT«t 
someumeson  the  bare  ground,  sometimes  in  nests  slightly  made  of  graT 
Mr.  Blackwall  has  recorded  the  curious  case  of  a  vellow  BunHnr»  r& 
r^'-^itrineiia)  gj^en Jn  "  Yarrell's  British  Birds."  S  ridriTUtand 
hatched  them  on  the  bare  ground  :  this  bird  genemlly  builds  on  or  ver|  c?ose 
to  the  ground,  but  a  case  is  recorded  of  its  having  built  at  a  height  o7seven 
feet     Anes    of  a  Chaffinch  {FrinnUla  .«/r>A*;'«  Annals  and  Mne  of  Nat 
History  '•  vol.  vi„,  1842,  p.  281)  bus  been  described,  which  was  bound  by  a 
piece  of  whipcord  passing  once  round  a  branch  of  a  pine  tree    and  then 
firmly  inter^voven  with  the  materials  of  the  nest :  the  n'^st  of  the  chaffinch 

with  lichen  ;  but  Mr.  Hewitson  ("  British  Oology,"  p.  7)  has  described  one 
m  which  bits  of  paper  were  used  for  lichen.  The  iVirush  (TwS 
budds  in  bushes,  but  sometimes,  when  bushes  abound,  in  holes  of  3  or 
under  sheds;  and  two  cases  are  known  of  its  having  built  JtualhSn  the 
ground  in  long  grass  and  under  turnip-leaves  (W.  Thompson  "S  H  st 
Bev  W  h  "i- ''  ^-  J''  =  ^'''''\"  Il^"«tration8  of  .nstir^t!"'p.  219).  The 
?r-  VV.D.  Fox  informs  me  that  an  "eccentric  pair  of  blackbirds " 
(T.  merula)   for  three  consecutive  years  built   in  ivv  against  a  wall    and 

ri^'/j."'^?''""  "'f,*-^'*^  ^^"'^  l>ors..hair,  thoughts  was  nSg  to 
tempt  them  to  use  this  material :    the  eggs  also  were  not  suotted      Tb« 

neZ  ^„r"«»*  "''f--  has  described  (in  "Mewitson's  British  Oo  ogy  ")^tL 
nests  of  two  Redstarts,  of  which  one  alone  was  lined  with  a  nrofif<,inn  nf 
white  feathers.  The  Golden-crested  Wren  (Mr.  ShrvJlJl'-Lir  Trans  " 
vol  xy,p  14)  usually  builds  an  open  nest  attached  to  the  under  side  of '* 
flr-branch,  but  sometimes  oa  the  branch,  and  Mr.  Sheppard  has  seen  one 

pendulous  with  a  hole  on  one  side."  Of  the  woudpvfnl  nif  «*  !i  t  r 
Weaver-bird  (PloceusPMippensis,  "  Proc  W  C"  Julytr  isl^?)  abtu? 
one  or  two  in  every  fifty  have  an  upper  chamber,  in  which  tL  male's  nest 
grooved  by  ne  widening  of  the  stem  of  the  nest^ith  a  pent  ho^se  aSdd 
InnH  J  ^'"  ^°"^^'<1''  by  adding  two  general  remarks  on  this  head  by  two 
good  observers  (Sheppard  in  "Linn.  Trans  "vol  xv  n  id,  L^  Tai„  t  n 
quoted  by  Yarrell.  "^^ritish  Birds,"  vol.?  p.  444)    ' -^TWe  aJe  Iw^^^^^^^^^^ 

nesr'''"irL°vTr'"^  -^^^^r.  *^1^"^^-'  for^hrbunc^rgS 

nests.  It  18  evident,    says  Mr.  Blackwall,  "  that  birds  of  the  same  snecies 

possess  the  constructive  powers  in  very  different  degrees  of  perfection  for  the 
of  othl!'"'"'"^^"'^''  ^'^  '"^^^^^  '^  ^  -anne^reatly^uperior  to  those 
r.y.  j!.Tr  °^  th^^oes  above  given,  such  as  the  Totanus  either  making  a  nest 
orbuildmg  on  the  bare  ground,  or  tl-.at  of  the  Water-ouzel  maki^f  Jr  not 
making  a  dome  to  its  nest,  ought,  perhaps,  to  be  calledTdrblelnstincJ 

fw  t?:irrs'zv  f  s  *''.^  t'  ^?^"""f  ^^^  «^  ^  doubitstinc  wS 

1  Jiave  met  w  th,  is  that  of  the  St/lna  cisticola  given  by  Dr.  P.  Savi  f"  Anns 
des  Sc  Nat.,  '  tome  ii,  p,  126).  This  bird  in  Pisa  annually  makes  two  neZ-" 
he  autumnal  nest  is  formed  by  lea.es  being  sewn  together  wShspiS^web; 
»nd  the  down  of  plants,  and  is  placed  in  marshes  ;  the  vernal  nest  is  ullced 
m  tufts  of  grass  m  corn-fields,  and  the  leaves  are  not  sewn  togetS;  but  tS 


i 

a. 


m 


if      f 


372 


MENTAL  EVOLUTION  IN  ANIMALS. 


■ides  are  thiolcer  and  very  diflbrent  materials  are  used.  In  such  cases,  as  wm 
formerly  remarked  with  respect  to  corporeal  structures,  a  great  and  apparently 
abrupt  change  might  be  elTected  in  the  instinct  of  a  bird  by  one  form  alone 
of  the  nest  being  retained. 

In  some  cases,  when  the  same  species  ranges  into  a  different  climate,  tha 
nest  differs  ;  the  Artamus  sordidus  in  Tasmania  builds  a  larger,  more  com- 
pact, and  neater  nest,  than  in  Australia  (Gould's  "Birds  of  Australia"). 
The  Sterna  minuta,  according  to  Audubon  ("  Anns,  of  Nat.  Hist,,"  vol.  ii, 
1839,  p.  462),  in  the  southern  and  middle  U.  States  merely  scoops  a  slight 
hollow  in  the  sand ;  "  but  on  the  coast  of  Labrador  it  makes  a  very  snug  nest, 
formed  of  dry  moss,  well  matted  together  and  nearly  as  large  as  that  of  the 
Turdus  migratorius."  Those  individuals  of  Icterus  BaUjmore  (Peabody  in 
"Boston  Journ.  of  I«lat.  Hist.,"  vol.  iii,  p.  97)  "which  build  in  the  south 
make  their  nests  of  light  moss,  which  allows  the  air  to  pass  through,  and 
complete  it  without  lining ;  while  in  the  cool  climate  of  New  England  they 
make  their  nests  of  soft  substances  closely  woven  with  a  warm  lining." 

Habitations  of  Mammals. — On  this  head  I  shall  make  but 
few  remarks,  having  said  so  much  on  the  nests  of  Birds. 
The  buildings  erected  by  the  Beaver  have  long  been  cele- 
brated ;  but  we  see  one  step  by  which  its  wonderful  instincts 
might  have  been  perfected,  in  the  simpler  house  of  an  allied 
animal,  the  Musk  Eat  (Fiber  zibethims)  which,  however, 
Hearne*  says  is  something  like  that  of  the  Beaver.  The 
solitary  Beavers  of  Europe  do  not  practise,  or  have  lost  the 
greater  part  of  their  constructive  instincts.  Certain  species 
of  Eats  now  uniformly  inhabit  the  roofs  of  houses,t  but  other 
species  keep  to  hollow  trees — a  change  analogous  to  that  in 
swallows.  Dr.  Andrew  Smith  informs  me  tliat  in  the  unin- 
habited parts  of  S.  Africa  the  hya3nas  do  not  live  in  burrows, 
whilst  in  the  inhabited  and  disturbed  parts  they  do.|  Several 
mammals  and  birds  usually  inhabit  burrows  made  by  other 
species,  but  when  such  do  not  exist,  they  excavate  their  own 
habitations.  § 

In  the  genus  Osmia,  one  of  the  Bee  family,  the  several 
species  not  only  offer  the  most  remarkable  differences,  as 
described  by  Mr.  F.  Smith]  |  in  their  instincts ;  but  the  indi- 
viduals of  the  same  species  vary  to  an  unusual  degree  in  this 
respect ;  thus  illustrating  the  rule,  which  certainly  seems  to 

•  Jlearne^s  Travels,  p.  380.  Hearne  has  given  the  best  description  (pp. 
227-236)  ever  published  of  the  habits  of  the  Beaver. 

t  Rev.  L.  Jenyns  in  lAnn.  Trans.,  vol.  xvi,  p.  166. 

j  A  case  sometimes  quoted  of  Hares  having  made  burrows  in  an  exposed 
situation  {Anns,  of  Nat.  Hist.,  vol.  v,  p.  362),  seems  to  me  to  require  verifica* 
tion :  were  not  the  old  rabbit-burrows  used  ? 

§  Zoology  of  the  Voyage  of  the  Beagle,  "  Mammalia,"  p.  90. 

II  Catalogue  of  British  Hymenoptera,  1855,  p.  158. 


APPENDIX. 


373 


hold  in  corporeal  structures,  namely,  that  the  parts  which 
differ  most  in  allied  species,  are  apt  also  to  vary  most  in  the 
same  species.  Another  Bee,  the  Megachile  maritima,  as  I  am 
informed  by  Mr.  Smith,  near  the  sea  makes  its  burrows  in  the 
sand-banks,  whilst  in  wooded  districts  it  bores  holes  in  posts* 

I  have  now  discussed  several  of  the  most  extraordinary 
classes  of  instincts ;  but  I  have  still  a  few  miscellaneous 
remarks  which  seem  to  me  worth  making.  First  for  a  few 
cases  of  variation  which  have  struck  me :  a  spider  which  had 
been  crippled  and  could  not  spin  its  web,  changed  its  habits 
from  compulsion  into  hunting — which  is  the  regular  habit  of 
one  large  group  of  spiders.f  Some  insects  have  two  very 
different  instincfts  under  different  circumstances,  or  at  different 
times  of  life ;  and  one  of  the  two  miglit  through  natural  selec- 
tion be  retained,  and  so  cause  an  apparently  abrupt  difference 
in  instinct  in  relation  to  the  insects'  nearest  allies :  thus  the 
larva  of  a  beetle  (the  Ciomis  scraphularice),  when  bred  on  the 
scrophularia,  exudes  a  viscid  substance,  which  makes  a  trans- 
parent bladder,  within  which  it  undergoes  its  metamorphosis  ; 
but  the  larva  when  naturally  bred,  or  transported  by  man,  on 
to  a  verbascum,  becomes  a  burrower,  and  und(!rgoes  its  meta- 
morphosis within  a  leaf  J  In  the  caterpillars  of  certain  moths 
there  are  two  great  classes,  those  which  burrow  in  the  paren- 
chyma of  leaves,  and  those  which  roll  up  leaves  with  consum- 
mate skill :  some  few  caterpillars  in  their  early  age  are 
burrowers,  and  then  become  leaf -rollers ;  and  this  change  was 
justly  considered  so  great,  that  it  was  only  lately  discovered 
that  the  caterpillars  belonged  to  the  same  species.  §  The 
Angoumois  moth  usually  has  two  broods:  the  first  are 
hatched  in  the  spring  from  eggs  laid  in  the  autumn  on  grains 
of  corn  stored  in  granaries,  and  then  immediately  take  flight 
to  the  fields  and  lay  their  eggs  on  the  standing  corn,  instead 
of  on  the  naked  grains  stored  all  round  them :  the  moths  of 
the  second  brood  (produced  from  the  eggs  laid  on  the  standing 
corn)  are  hatched  in  the  granaries,  and  then  do  not  leave  the 
granaries,  but  deposit  their  eggs  on  the  grains  around  them  ; 
and  from  these  eggs  proceed  the  vernal  brood  which  have  the 

*  [Here  follows  a  section  on  the  instincts  of  Parasitism,  Slave-making,  and 
Cell-making,  which  is  published  in  the  Origin  of  Species. — Q-.  J.  R.J 
t  Quoted  on  authority  of  Sir  J.  Banks  in  Journal  Linn.  Soo. 
X  p.  Huber  in  Mem.  Soc.  Phi/s.  de  Oenhve,  tome  x,  p.  33. 
§  Westwood,  in  Qai-denera'  Chronicle,  1852,  p.  261. 


wms 


374 


MENTAL  EVOLUTION  IN  ANIMALS. 


different  instinct  of  laying  on  the  standing  corn.*    Some  hunt- 
ing spiders,  when  they  have  eggs  and  young,  give  up  hunting 
and  spin  a  web  wherewith  to  catcli  prey:  this  is  the  case 
with  a  Sulticus,  which  lays  its  eggs  within  snail-shells,  and  at 
that  time  spins  a  large  vertical  web.f     The  pupie  of  a  species 
of  Formica  are  sometvmesX  uncovered,  or  not  enclosed  within 
cocoons ;  this  certainly  is  a  highly  remarkable  variation ;  the 
same  thing  is  said  to  occur  with  the  con^mon  I'ulex.     Lord 
Brougham§  gives  us  a  remarkable  case  of  instinct,  namely,  tho 
chicken  within  the  shell  pecking  a  hole  and  then  "  chipping 
with  its  bill-scale  till  it  has  cut  off  a  segment  from  the  shell 
It  always  moves  from  right  to  left,  and  it  always  cuts  off  the 
segment  from  the  big  end."    But  the  instinct  is  not  quite  so 
mvariable,  for  I  was  assured  at  the  Eccalobeion  (May,  1840) 
that  cases  have  occurred  of  chickens  having  commenced  so 
cbse  to  the  broad  end,  that  they  could  not  escape  from  the 
hole  thus  made,  and  had  consequently  to  commence  chipping 
again  so  as  to  remove  another  and  larger  rim  of  sliell :  more- 
over occasionally  they  have  begun  at  the  narrow  end  of  the 
shell.    The  fact  of  the  occasional  regurgitation  of  its  food  by 
the  Kangarooll  ought,  perhaps,  to  be  considered  as  due  to  an 
mtermediate   or  variable  modification  of  structure,   rather 
than  of  instinct;  but  it  is  worth  notice.      It  is  notorious 
that  the  same  species  of  Bird  has  slightly  different  vocal 
powers  in  different  districts;    and  an   excellent    observer 
remarks  that  "  an  Irish  covey  of  Partridges  springs  without 
uttering  a  call,  whilst  on  the  opposite  coast  the  Scotch  covey 
shrieks  with  all  its  might  when  sprung."1f     Bechstein  says 
that  from  many  years'  experience  he  is  certain  that  in  the 
nightingale  a  tendency  to  sing  in  the  middle  of  the  night  or 
in  the  day  runs  in  families  and  is  strictly  inherited.**     It  is 
remarkable  that  many  birds  have  the  capacity  of  piping  long 
and  difficult  tunes,  and  others,  as  the  Magpie,  of  imitating 


•  Bonnet,  quoted  by  Kirby  and  Spence,  Entomologtf,  vol.  ii,  p.  480. 

t  DugSs  in  Anns,  des  Sci.  Nat.,  2nd  series,  tome  vi,  p.  196. 

X  F.  Smith  in  Trans.  Ent.  Soc,  vol.  iii,  N.S.,  Pt.  iii,  p.  97}  and  De  Geer, 
quoted  by  Kirby  and  Spence,  Entomology,  vol.  iii,  p.  227. 

§  Dissertation  on  Natural  Theology,  vol.  i,  p.  117. 

II  W.  C.  Martin  in  Mag.  of  Nat.  Hist.,  N.S.,  vol.  ii,  p.  323. 

f  W.  Thompson,  in  Nat.  Hist.  Ireland,  vol.  ii,  p.  65,  says  that  he  has 
observed  this,  and  that  it  is  well  known  to  sportsmen. 

**  Stuben-vogel,  1840,  s.  323.  See  on  different  powers  of  Bingini?  in 
different  places,  a.  206  and  265. 


iiL    i 


APPENDIX. 


375 


all  sorts  of  sounds,  and  yet  that  in  a  state  of  nature  they 
nevor  display  these  powers.* 

As  there  is  often  much  difficulty  in  imagining  how  an 
instinct  could  first  have  arisen,  it  may  be  worth  while  to  give 
a  few,  out  of  many  cases,  of  occasional  and  curious  habits, 
which  cannot  be  considered  as  regular  instincts,  but  which 
might,  according  to  our  views,  give  rise  to  such.      Thus, 
several  cases  are  on  recordf  of  insects  which  naturally  have 
very  different  habits  having  been  hatched  within  the  bodies 
of  men — a  most  rcimurkable  fact  considering  the  temperature 
to  which  they  have  been  exposed,  and  which  may  explain 
the  origin  of  the  instinct  of  the  Gad-ily  or  (Estrus.     We  can 
see  how  the  closest    association    might   be  developed    in 
Swallows,  for  LamarckJ  saw  a  dozen  of  these  birds  aiding  a 
pair,  whose  nest  had  been  taken,  so  effectually  that  it  was 
completed  on  the  second  day ;   and  from  the  facts  given  by 
Macgillivray§  it  is  impossible   to   doubt  that  the  ancient 
accounts  are  true  of  the  Martins  sometimes  associo'  1  '\g  and 
entombing  alive  sparrows  which  have  taken  possession  of  one 
of  their  nests.     It  is  well  known  that  the  Hive-bees  which 
have  been  neglected  "  get  a  habit  of  pillaging  from  their  more 
industrious  neighbours,"  and  are  then  called  corsairs ;  and 
Huber  gives  a  far  more  remarkable  case  of  some  Hive-bees 
which  took  almost  entire  possession  of  the  nest  of  a  Humble- 
bee,  and  for  three  weeks  the  latter  went  on  collecting  honey 
and  then  regorged  it  at  the  solicitation,  without  any  violence, 
of  the  Humble-bee.||     "We  are  thus  reminded  of  those  Gulls 
(Lcstris)  which  exclusively  live  by  pursuing  other  gulls  and 
compelling  them  to  disgorge  their  food.lf 

In  the  Hive-bee  actions  are  occasionally  performed  which 

•  Blackwall's  Researches  in  Zoology,  1834,  p.  158.  Cuvier  long  ago 
remarked  that  all  the  passeres  have  apparently  a  siiuilar  structure  in  their 
vocal  organs;  and  yet  only  a  few,  and  these  the  males,  sing;  showing  that 
fitting  structure  does  not  always  give  rise  to  corresponding  habits.  [Concern- 
ing birds  which  imitate  sounds  when  in  captivity  not  doing  so  in  a  state  of 
nature,  see  p.  222,  where  there  is  evidence  of  certain  wild  birds  imitating  the 
sounds  of  other  species. — G.  J.  R.] 

t  Rev.  L.  Jenyns,  Observations  in  Nat.  Hist.,  1846,  p.  280. 

J  Quoted  by  Geoffry  St.  Hilaire  in  Anns,  des  Mus.,  tome  ix,  p.  471. 

§  British  Birds,  vol.  iii,  p.  591. 

II  Kirby  and  Spence,  Entomology,  voL  ii,  p.  207.  The  case  given  by 
Huber  is  at  p.  119. 

^  There  is  reason  to  suspect  (Macgillivray,  British  E'  w,  vol.  v,  p.  500) 
that  some  of  the  species  can  only  digest  lood  which  has  been  partially 
digested  by  other  birds. 


'I 


:ii 


),l 


376 


MENTAL  EVOLUTION  IN  ANIMALS. 


we  must  ranlf  amongst  the  most  wonderful  of  instincts ;  and 
yet  these  instincts  must  often  have  beta  dormant  durincr 
many  generations:  1  refer  to  the  death  of  the  queen,  wheS 
several  worker-larvae  are  necessarily  destroyed,  and  beincr 
placed  m  large  cells  and  reared  on  royal  food,  are  thuS 
rendered  fertile :  so  again  when  a  hive  has  its  queen,  the 
males  are  all  infallibly  killed  by  the  workers  in  autvmn  :  but 

,  A»-r.f  ""^  ^"^®"'  "°*  ^  «"igle  drone  is  ever  de- 
stroyed. Perliaps  a  rr.y  of  light  is  thrown  bv  our  theory  on 
these  mysterious  but  well  ascertained  facts,"by  considering 
that  the  analogy  of  other  members  of  the  Bee  family  would 
lead  us  to  believe  that  the  Hive-bee  is  descended  from  other 
iiees  which  i-gularly  had  many  females  inhabiting  the  same 
nest  during  the  whole  season,  and  which  never  destroyed 
their  own  males ;  ^o  that  not  to  destroy  the  males  and  to 
give  the  normal  food  to  additional  larva,  perhaps  is  only  a 
reversion  to  an  ancestral  instinct,  and,  as  in  the  case  of 
corporeal  structures  reverting,  is  apt  to  occur  after  many 
generations.f  -^ 

I  will  now  refer  to  a  few  cases  of  special  difficulty  on  our 
theory— most  of  them  parallel  to  those  which  I  adduced 
when  discussing  in  Chapter  VIII  corporeal  structures  Thus 
we  occasionally  meet  with  the  same  peculiar  instinct  in 
animals  widely  remote  in  the  scale  of  nature,  and  which  conse- 
quently cannot  have  derived  the  peculiarity  from  community 
of  descent  The  Molothrus  (a  bird  something  like  a  starlin/) 
ot  N.  and  S.  America  has  precisely  the  same  habits  with  the 
Uickoo ;  but  parasitism  is  so  common  throughout  nature  that 
this  coincidence  is  not  veiy  surprising.  The  parallelism  in 
instinct  between  the  White  Ants,  belonging  f,o  the  Neurop- 
tera  and  ants  belonging  to  the  Hymenoptera,  is  a  far  more 
wonderlul  fact;  but  the  parallelism  seems  to  be  very  far  from 
close.  Perhaps  as  remarkable  a  case  as  any  on  record  of  the 
same  instinct  having  been  independently  acquired  in  two 
animals  very  remote  from  each  other  in  relationship,  is  that 
ot  a  I^europterous  and  a  Dipterous  larva  digging  a  conical 

*  Kirby  and  Spence,  Dntomologif,  vol.  ii,  pp.  510-13. 

TrillitJ-  r^'T'"^  1^?  ^T"°"  ^^^  '^^''^  ^""^  «o  "^'^"y  drones  as  to  require 
iiUing,  see  ^m,««Z  Intelhgenoe  p.  166,  .vbere  I  suggest  chat  imong  the 
ancestors  of  the  Hive-bee  the  males  may  have  been  of  use  as  ..ovkers.  ^But 
possibly  the  drones  may  even  now  be  of  use  as  nurses  to  the  lar-se.  for  I  am 
told  ^  an  exponenced.  bee-keeper  that  he  believes  this  to  b<  the  case.-- 


li^,   >i.. 


APPENDIX. 


377 


pit-fall  in  loose  sand,  lying  motionless  at  the  bottom,  and  if 
the  prey  is  about  to  escape,  casting  jets  of  sand  all  round.* 

It  has  been  asserted  that  animals  are  endowed  with 
instincts,  not  for  their  own  individual  good,  or  for  that  of 
their  own  social  bodies,  but  for  the  good  of  other  species, 
though  leading  to  their  own  destruction :  it  has  been  said 
that  fishes  migrate  that  birds  and  other  animals  may  prey  on 
them  :  f  this  is  impossible  on  our  theory  of  natural  selection- 
of  self-profitable  modification  of  instinct.  But  I  have  met 
with  no  facts  in  support  of  this  belief  worthy  of  considera- 
tion. Mistakes  of  instinct,  as  we  shall  presently  see,  may  in 
some  cases  do  injury  to  a  species  and  profit  another;  one 
species  may  be  compelled,  or  even  apparently  induced  by 
persuasion,  to  yield  up  its  food  or  secretion  to  another  species; 
but  that  any  animal  has  been  specially  endowed  with  an 
instinct  leading  to  its  own  destruction  or  harm,  I  cannot 
believe  without  better  evidence  than  has  hitherto  been 
adduced. 

An  instinct  performed  only  once  during  the  life  of  an 
animal  appears  at  first  sight  a  great  difficulty  on  our  theory ; 
but  if  indispensable  to  the  animal's  existence,  there  is  no 
valid  reason  why  it  should  not  have  been  acquired  through 
natural  selection,  like  corporeal  structures  used  only  on  one 
occasion,  like  the  hard  tip  to  the  chicken's  beak,  or  like  the 
temporary  jaws  of  the  pupa  of  the  Caddis-fly  or  Phryganea, 
which  are  exclusively  used  for  cutting  open  the  silken  doors 
of  its  curious  case,  and  which  are  then  thrown  off  for  ever.$ 
Nevertheless  it  is  impossible  not  to  feel  unbounded  astonish- 
ment, when  one  reads  of  such  cases  as  that  of  a  caterpillar 
first  suspending  itself  by  its  tail  to  a  little  hillock  of  silk 
attached  to  some  object,  and  then  undergoing  its  meta- 
morphosis; then  after  a  time  splitting  open  one  side  and 
exposing  the  pupa,  destitute  of  limbs  or  organs  of  sense  and 
lying  loose  within  the  loiver  part  of  the  old  bag-like  split 
skin  of  the  caterpillar  :  this  skin  serves  as  a  ladder  which  the 
pupa  ascends  by  seizing  on  portions  between  the  creases  of 


its  abdominal  segments. 


and 


then   searching  with  its  tail. 


which  is  provided  with  little  hooks,  thus  attaches  itself,  and 


*  Kirby  and  Spence,  Entomology,  vol.  i,  pp.  429-435. 
t  Linns)U3   in    Amoenitates   AcademiccB,    vol.  ii ;  and  Prof.  Alison    on 
Instinct"  in  Todd's  Cycl.  of  A  not.  and  Physiol.,  p.  15. 
X  Kirby  and  Spence,  Entomology,  vol.  iii,  p.  287. 


378 


MENTAL  EVOLUTION  IN  ANIMALS. 


I     "1 


I'll      i 


afterwards  disengages  and  casts  off  the  skin  which  had  served 
It  tor  a  ladder*      I  am  tempted  to  give  one  other  analogous 
case,  that  of  the  caterpillar  of  a  Butterfly  (TheMa),  vfhich 
teeds  withm  the  pomegranate,  but  when  fuU  fed  gnaws  its 
way  out  (thus  making  the  exit  of  the  butterfly  possible  before 
Its  wings  are  fully  expanded),  and  then  attaches  with  silk 
threads  the  point  to  the  branch  oi  the  tree,  that  it  may  not 
tall  before  the  metamorphosis  is  complete.      Hence,  as  in  so 
many  other  cases,  the  larva  works  on  this  occasion  for  the 
safety  of  the  pupa  and  of  the  mature  insect.      Our  astonish- 
ment at  this  manoeuvre  is  lessened  in  a  very  sli<»ht  de^n-ee 
when  we  hear  that  several  caterpillars  attach  mo°re  or  less 
perfectly  with  silken  threads  leaves  to  the  stems  for  their 
own  safety;  and  that  another  cat-rpillar,  before  chan<nnf' 
into  a  pupa,  bends  the  edges  of  a  leaf  together,  coats  "on? 
surface  with  a  silk  web,  and  attaches  this  web  to  the  foot- 
stalk  and  branch  of  the  tree;   the  leaf  afterwards  becomes 
brittle  and  separates,  leaving  the  silken  cocoon  attached  to 
the  footstalk  and  branch  ;  in  this  case  the  process  differs  but 
little  from  the  ordinary  formation  of  a  cocoon  and  its  attach- 
ment to  any  object.f 

A  reaUy  far  greater  difficulty  is  offered  by  those  cases  in 
wfiich  the  instincts  of  a  species  differ  greatly  from  those  of 
Its  related  forms.  This  is  the  case  with  the  above  mentioned 
Ihekla  of  the  pomegranate;  and  no  doubt  many  instances 
could  be  collected.  But  we  should  never  forget  what  a  small 
proportion  the  living  must  bear  to  the  extinct  amongst 
insects,  the  several  orders  of  which  have  so  long  existed  on 
this  earth.  Moreover,  just  in  the  same  way  as  with  corporeal 
structures,  I  have  been  surprised  how  often  when  I  thou-^ht 
I  had  got  a  case  of  a  perfectly  isolated  iustincc,  I  found°on 
further  enquiry  at  least  some  traces  of  a  graduated  series. 

I  have  not  rarely  felt  that  small  and  trifling  instincts 
were  a  greater  difficulty  on  our  theory  than  those  which 
have  so  justly  excited  the  wonder  of  mankind;  for  an 
instinct,  if  really  of  no  considerable  importance  in  the 
struggL  for  life,  could  not  be  modified  or  formed  through 
natural  selection.  Perhaps  as  striking  an  instance  as  can  be 
given  IS  that  of  the  worker  of  the  Hive-bee  arranged  in  files 
and  ventilating,  by  a  peculiar  movement  of  their  wings,  the 

•  Kiiby  and  Spence,  Enlomologi/,  vol.  iii,  pp.  208-11. 
t  J.  0.  Westwood  in  Trans.  Entomol.  Soc,  vol.  ii,  p.'l. 


APPENDIX. 


S79 


well-closed  hive:  this  ventilation  has  been  artificially  imi- 
tated* and  as  it  is  carried  on  even  Muring  winter,  there  can 
be  no  doubt  that  it  is  to  bring  in  free  air  and  displace  the 
carbonic  acid  gas :  therefore  it  is  in  truth  indispensable,  and 
we  may  imagine  the  stages— a  few  bees  first  going  to  the 
orifice  to  fan  themselves— by  which  the  instinct  might  have 
been  arrived  at.  We  admire  the  instinctive  caution  of  the 
hen-pheasant  which  leads  her,  as  Waterton  remarked,  to  fly 
from  her  nest  and  so  leave  no  track  to  be  scented  out  by 
beasts  of  prey ;  but  this  again  may  well  be  of  high  import- 
ance to  the  species.  It  is  more  surprising  that  instinct 
should  lead  small  nesting  birds  to  remove  their  broken  eggs 
and  the  early  mutings,  whereas  with  partridges,  the  young  of 
which  immediately  follow  their  parents,  the  broken  eggs  are 
left  round  the  nest ;  but  when  we  hear  that  the  nests  of 
those  birds  (Halcyonidje)  in  which  the  mutings  are  not 
enclosed  by  a  film,  and  so  can  hardly  be  removed  by  the 
parent,  are  thus  "rendered  very  conspicuous  ;"t  and  when 
we  remember  how  many  nests  are  destroyed  by  cats,  we 
cannot  any  longer  consider  them  instincts  of  trifling  import- 
ance. But  some  instincts  one  can  hardly  avoid  looking  at  as 
mere  tricks,  or  sometimes  as  play :  an  Abyssinian  pigeon 
when  fired  at,  phinges  down  so  as  to  almost  touch  the  sports- 
man, and  then  mounts  to  an  immoderate  height :  J  the 
Bizcacha  (Lagostomus)  almost  invariably  collects  all  sorts  of 
rubbish,  bones,  stones,  dry  dung,  &c.,  near  its  burrow : 
Guanacoes  have  the  habit  of  returning  (like  Flies)  to  the 
same  spot  to  drop  their  excrement,  and  I  saw  one  heap  eight 
feet  in  diameter ;  as  this  habit  is  common  to  all  the  species 
of  the  genus,  it  must  be  instinctive,  but  it  is  hard  to  believe 
that  it  can  be  of  any  use  to  the  animal,  though  it  is  to  the 
Peruvians,  who  use  the  dried  dung  for  fuel.§  Many  analogous 
facts  could  probably  be  collected. 

Wonderful  and  admirable  as  most  instincts  are,  yet  they 
cannot  be  considered  as  absolutely  perfect :   there  is  a  con- 

•  Kirby  and  Spence,  "Entomology,  vol.  ii,  p  193. 

t  Blyth  in  Mag.  of  Nat.  Hist.,  N.S.,  vol.  ii. 

X  Brace's  Travels,  vol.  v,  p.  187. 

§  See  my  Journal  of  Researches,  p.  167  for  the  Guanaco;  for  the 
Bizcacha,  p.  145.  Many  odd  instincts  are  connected  with  the  excrement  of 
animals,  as  with  the  wild  Horse  of  S.  America  (see  Atara's  Travels,  vol.  i, 
p.  373),  with  the  common  House  Fly  and  with  Dof!;s;  see  on  the  urinary 
deposits  of  the  Hyrax,  Livingston's  Missionarjf  Travels,  p.  22. 


W 


mm 

mm 


380 


MENTAL  EVOLUTION  IN  ANIMALS. 


f  '' 


i'-\ 


m. 


■f 


stant  struggle  going  on  throughout  nature  between  the 
instinct  of  the  one  to  escape  its  enemy  and  of  the  other  to 
secure  its  prey.  If  the  instinct  of  the  Spider  be  admirable, 
that  of  the  Fly  which  rushes  into  its  toils  is  so  far  inferior. 
Eare  and  occasional  sources  of  danger  are  not  avoided :  if 
death  inevitably  ensues,  and  creatures  cannot  have  learnt  by 
seeing  others  suffer,  it  seems  that  no  guardian  instinct  is 
acquired :  thus  the  ground  within  a  solfortara  in  Java  is 
strewed  with  the  carcases  of  tigers,  birds,  and  masses  of 
insects  killed  by  the  noxious  exhalations,  with  their  flesh, 
hairs,  and  feathers  preserved,  but  their  bones  entirely  con- 
sumed.* Migratory  instinct  not  rarely  fails,  and  the  animals, 
as  we  have  seen,  are  lost.  What  ought  we  to  think  of  the 
strong  impulse  which  leads  Lemmings,  Squirrels,  Ermines,! 
and  many  other  animals  which  are  not  regularly  migratory, 
occasionally  to  congregate  and  pursue  a  headlong  course, 
across  great  rivers,  lakes,  and  even  into  the  sea,  where  vast 
numbers  perish ;  and  ultimately  it  would  appear  that  all 
perish  ?  The  country  being  overstocked  seems  to  cause  the 
original  impulse ;  but  it  is  doubtful  whether  in  all  cases 
scarcity  actually  prevails.  The  whole  case  is  quite  inex- 
plicable. Does  the  same  feeling  act  on  these  animals  which 
causes  men  to  congregate  under  distress  and  fear ;  and  are 
these  occasional  migrations,  or  rather  emigrations,  a  forlorn 
hope  to  find  a  new  and  better  land  ?  The  occasional  emigra- 
tions of  insects  of  many  kinds  associated  togei  her,  which,  as 
I  have  witnessed,  must  perish  by  countless  myriads  in  the 
sea,  are  still  more  remarkable,  as  they  belong  to  families  none 
of  which  are  naturally  social  or  even  migratory.J 

*  Von  Buch,  Descript.  Phys.  des  lies  Canaries,  1836,  p.  423,  on  the 
excellent  authority  of  M.  ReinwardtB. 

t  L.  Lloyd,  Scandinavian  Adventure,  1854,  vol.  ii,  p.  77,  gives  an  excellent 
account  of  the  migration  of  Lemmings:  when  swimming  across  a  lake,  if 
they  meet  a  boat,  they  crawl  up  one  side  and  down  the  opposite  side.  Great 
migrations  took  place  in  1789,  1807,  1808,  1813,  1323.  Ultimately  all  seem 
to  perish.  See  Hogstrom's  account  in  Sicedish  Acts,  vol.  iv,  1763,  of  ermines 
migrating  and  entering  the  sea.  See  Bachman's  account  in  Mag.  of  Nat.  Hist., 
K.S.,  vol.  iii,  1839,  p.  229,  of  the  migration  of  squirrels;  they  are  bad 
swimmers  and  get  across  great  rivers. 

X  Mr.  Spence  in  his  Anniversary  address  to  the  Entomological  Society, 
1848,  has  some  excellent  remarks  on  the  occasional  migration  of  insects,  and 
shows  how  inexplicable  the  case  is.  See  also  Kirby  and  Spence,  Entomology, 
vol.  ii,  p.  12;  and  Weissenborn  in  Mag.  of  Nat.  Hist.,  N.S.,  1834,  vol.  iii, 
p.  516,  for  interesting  details  on  a  great  migratioa  of  Libellulee,  generally 
along  the  course  of  rivers. 


APPENDIX. 


381 


The  social  instinct  is  indispensable  to  some  animals, 
useful  to  still  more  for  the  ready  notice  of  danger,  and  appa- 
rently only  pleasant  to,  some  few  animals.  But  one  cannot 
avoid  thinking  that  this  instinct  is  carried  in  some  cases  to 
an  injurious  excess:  the  antelopes  in  S.  Africa  and  the 
Passenger  Pigeons  in  N.  America  are  followed  by  hosts  of 
carnivorous  beasts  and  birds,  which  could  hardly  be  supported 
in  such  numbers  if  their  prey  were  scattered.  The  Bison  of 
N".  America  migrates  in  such  vast  bodies,  that  when  they 
come  to  narrow'  passes  in  the  river-cliifs,  the  foremost,  accord- 
ing to  Lewis  and  Clarke(?)*  are  often  pushed  over  the 
precipice  and  dashed  to  pieces.  Can  we  believe  when  a 
wounded  herbivorous  animal  returns  to  its  own  herd  and  is 
then  attacked  and  gored,  that  this  cruel  and  very  common 
instinct  is  of  any  service  to  the  species  ?  It  has  been  re- 
markedt  that  with  Deer,  only  those  which  have  been  much 
chased  with  dogs  are  led  by  a  sense  of  self-preservation  to 
expel  their  pursued  or  wounded  companion,  who  will  bring 
danger  on  the  herd.  But  the  fearless  wild  elephants  will 
"  ungenerously  attack  one  which  has  escaped  into  the  jungles 
with  the  bandages  still  upon  its  legs."|  And  I  have  seen 
domestic  pigeons  attack  and  badly  wound  sick  or  young  and 
fallen  birds. 

The  cock-pheasant  crows  loudly,  as  everyone  may  hear, 
when  going  to  roost,  and  is  thus  betrayed  to  the  poacher.  §  The 
wild  Hen  of  India,  as  I  am  informed  by  Mr.  Blyth,  chuckles 
like  her  domesticated  offspring,  when  she  has  laid  an  egg; 


•  [The  note  of  interrogation  is  in  the  MS. — Q-.  J.  E.] 

t  W.  Scrope,  Art  of  Deer  Stnlking,  p.  23. 

J  Corse,  in  Asiatic  Researches,  vol.  iii,  p.  272.  This  fact  is  the  more 
Btrange  as  an  Elephant  which  had  escaped  from  a  pit  was  seen  by  many 
witnesses  to  stop  and  assist  witli  his  trunk  his  companion  in  getting  out  of 
the  pit  {Athenceum,  1810,  p.  238).  Capt.  Sulivan,  R.N.,  informs  me  that  he 
watched  for  more  than  half  an  hour,  at  the  Falkland  Islands,  a  Logger- 
headed  Duck  defending  a  wounded  Upland  Goose  from  the  repeated  attacks 
of  a  Carrion  Hawk.  The  upland  goose  first  took  to  the  water,  and  the  duck 
swam  close  alongside  her,  always  defending  her  with  its  strong  beak ;  when 
the  goose  crawled  ashore,  the  duck  followed,  going  round  and  round  her,  and 
when  the  goose  again  took  to  the  sea  the  duck  was  still  vigorously  defending 
her ;  yet  at  other  times  this  duck  never  associates  with  this  goose,  for  their 
food  and  place  of  habitation  are  utterly  different.  I  very  much  fear,  froui 
what  we  see  of  little  birds  chasing  hawks,  that  it  would  be  more  philosophical 
to  attribute  this  conduct  in  the  duck  to  hatred  of  the  carrion  hawk  rather 
than  to  benevol  r  -■  for  the  goose. 

§  Eev.  L.  Jt/;y,  3,  Observations  in  Natural  History,  1846,  p.  100. 
25 


!■ 


Vt 


t 


fil'l 


382 


MENTAL  EVOLUTION  IN  ANIMALS. 


and  the  natives  thus  discover  her  nest.  In  La  Plata  the 
Furnarius  builds  a  large  oven-like  nest  of  mud  in  as  con- 
spicuous a  place  as  possible,  on  a  bare  rock,  on  the  top  of  a 
post,  or  cactus-stem ;  *  and  in  a  thickly  peopled  country,  with 
mischievous  boys,  would  soon  be  exterminated.  The  great 
Butcher-bird  conceals  its  nest  very  badly,  and  the  male 
during  incubation,  and  the  female  after  her  eggs  are  hatched, 
betray  the  nest  by  their  repeated  harsh  cries.f  So  again  a 
kind  of  Shrew-mouse  at  the  Mauritius  continually  betrays 
itself  by  screaming  out  as  soon  as  approached.  Nor  ought 
we  to  say  that  these  failures  of  instinct  are  unimportant,  as 
principally  concerning  man  alone  ;  for,  as  we  see  instinctive 
wildness  directed  towards  man,  there  seems  no  reason  why 
other  instincts  should  not  be  related  to  him. 

The  number  of  eggs  of  the  American  Ostiich  scattered 
over  the  country,  and  so  wasted,  has  already  been  noticed. 
The  Cuckoo  sometimes  lays  two  eggs  in  the  same  nest,  leading 
to  the  sure  rejection  of  one  of  the  two  young  birds.  Flies,  it 
has  often  been  asserted,  frequently  make  mistakes,  and  lay 
their  eggs  in  substances  not  fitted  for  the  nourishment  of 
their  larvae.  A  SpiderJ  will  eagerly  seize  a  little  ball  of  cotton 
when  deprived  of  her  eggs,  embedded  as  they  are  in  a  silken 
envelope  ;  but  if  a  choice  be  given  her,  she  will  prefer  her  own 
eggs,  and  will  not  always  seize  the  ball  of  cotton  a  second 
time :  so  that  we  see  sense  or  reason  here  correcting  a  first 
mistake.  Little  birds  often  gratify  their  hatred  by  pursuing 
a  Hawk,  and  perhaps  by  so  doing  distract  its  attention  ;  but 
they  often  mistake  and  persecute  (as  I  have  seen)  any  inno- 
cent and  foreign  species.  Foxes  and  other  carnivorous 
beasts  often  destroy  far  more  prey  than  they  can  devour  or 
carry  away :  the  Bee  Cuckoo  kills  a  vast  number  more  bees 
than  she  can  eat,  and  "  unwisely  pursues  without  interruption 
this  pastime  all  the  day  long."§  A  queen  Hive-bee  confined 
by  Huber,  so  that  she  could  not  lay  her  eggs  in  worker  cells, 
would  not  deposit,  but  dropped  them,  upon  which  the 
workers  devoured  them.  An  unfertilized  queen  can  lay  only 
male  eggs,  but  these  she  deposits  in  worker  and  royal  cells— 
an  aberration  of  instinct  not  surprising  under  the  circum- 

*  Journal  of  Researches,  p.  95. 
t  Knapp.  Journal  of  a  Naturalist,  p.  188. 

j  These  facts  are  given  by  Dugfes   in  Anns,  des  So.  Nat,  2nd  series 
tome  vi,  p.  196. 

§  Bruce' s  Travels  H  Abyssinia,  vol.  v,  p.  179, 


APPENDIX. 


883 


!  circum> 


stances ;  but  the  workers  themselves  act  as  if  they  suffered 
m  their  instinct  from  the  imperfect  state  of  their  cmeen  for 
they  fed  these  male  larv^  with  royal  jelly  and  treat  ?hem 
as  they  would  a  real  queen."*  ButVat  Is  C  e  su?pr  si^ 
the  workers  of  Humble-bees  habitually  endeavour  to  seL'e 
and  devour  the  eggs  of  their  own  queens;    and  the  utmost 

V  Se»t      cr?r  i  "«^-««ly  adequate  to  prevenfthi 
violence  t      Can  this  strange  instinctive  habit  be  of  anv 

lZZlt:n^"r''L  ^'"^  the  innumerable  and  admirable 
instincts  al    directed   to  rear  and  multiply  youn-   can  we 

mtS"''^  ''""'^r^  ^P^^«^'  ^^^*  thistLge' aberrant 

?ue  bound,  ^^''^'p'^Ti  "'■'   ^''^   '^'    population   within 

due  bounds  ?       Can   the   instinct  which  leads   the  female 

spder  savagely  to  attack  and  devour  the  male  after  pSg 

with  himj   be  of    service   to  the   species  ?      The   Leas? 

of  her  husband  no  doubt  nourishes  her;   and  without  some 

better  explanation  can  be  given,  we  are  'thus  reduced  to  tl^e 

grossest  utilitarianism,  compatible,  it  must  be  confessed  wth 

the  theory  of  natural  selection.      I  fear  that  to  the  foreCln. 

cases  a  long  catalogue  could  be  added  ^"^e^o^"*, 

Conchcsion.—We  have  in  this  chapter  chiefly  considered 

the  instincts  of  animals  under  the  point  of  view  whether  it' s 

possible  that  they  could  have  been  acquired  through     he 

means  indicated  on  our  theory,  or  whether,\ven  if  the  simple? 

ones  could  have  been  thus  acquired,  others  are  so  complex 

and  wonderful  that  they  must  have  been  specially  endXd 

and  thus  overthrow  the  theory.      Bearing  in  mind  the  facts 

given  on  the  acquirement,  through  the  sefection  o?  self!oril 

LT>Sh?^7'.™°^'^''^^""  of  instinct,  or  through  training 

ZJt^M-  ''^'^  '?  'r '  '^P^^  ^^Sree  by  imitatioli,  of  here! 

ditary  actions  and  dispositions  in  our  domesticated  animals  • 

I'nstinotrnr''^'^'"'  ^'^^J'"'  ''  ^^^^"g  1^««  ti«^«)  to  the 
nstincts  ot  animals  in  a  state  of  nature :  bearing  in  mind 

t  at  n  a  state  of  nature  instincts  do  certainlv  vary  in  some 

slight  degree :  bearing  in  mind  how  very  geneivali;  L  fiS 

allied  but  distinct  animals  a  gradation  iS  the  more  complex 

nstincts,  which  show  that  it  is  at  least  possible  that  a  complex 

instinct  might  have  been  acquired  by  'successive  steps  [and 

then,  will  """'"  \  P-  '^^K.^  ^°"?  ^''*  °f  ''^^^^  i"«^^t8  ^'hich  either  in 
their  larval  or  mature  condition  will  devour  each  other  is  given 


ii:; 


IE 


m 


384 


MENTAL  EVOLUTION  IN  ANIMALS. 


In 


P-i- 


which  moreover  generally  indicate,  according  to  our  theory, 
the  actual  steps  by  which  the  instinct  has  been  acquired,  in 
as  much  as  we  suppose  allied  instincts  to  have  branched  off 
at  different  stages  of  descent  from  a  common  ancestor,  and 
therefore  to  have  retained,  more  or  less  unaltered,  the 
instincts  of  the  several  lineal  ancestral  forms  of  any  one 
species  :  bepring  all  this  in  mind,  together  with  the  certainty 
that  instincts  are  as  important  to  an  animal  as  their  generally 
correlated  structures,  and  that  in  the  struggle  for  life  under 
changing  conditions,  slight  modifications  of  instinct  could 
hardly  fail  occasionally  to  be  profitable  to  individuals,  I  can 
see  no  overwhelming  difficulty  on  our  theory.  Even  in  the 
most  marvellous  instinct  known,  that  of  the  cells  of  the 
Hive-bee,  we  have  seen  how  a  simple  instinctive  action  may 
lead  to  results  which  fill  the  'mind  with  astonishment. 

Moreover  it  seems  to  me  that  the  very  general  fact  of  the 
gradation  of  complexity  of  instincts  within  the  limits  of  the 
same  group  of  animals  ;  and  likewise  the  fact  of  two  allied 
species,  placed  in  two  distant  parts  of  the  world  and  sur- 
rounded by  wholly  different  conditions  of  life,  still  having 
very  much  in  common  in  their  instincts,  supports  our  theory 
of  descent ;  for  they  are  explained  by  it :  whereas  if  we  look 
at  each  instinct  as  specially  endowed,  we  can  only  say  that 
it  is  so.  The  imperfections  and  mistakes  of  instinct  on  our 
theory  cease  to  be  surprising  :  indeed  it  would  be  wonderful 
that  far  more  numerous  and  flagrant  cases  could  not  be 
detected,  if  it  were  not  that  a  species  which  has  failed  to 
become  modified  and  so  far  perfected  in  its  instincts  that  it 
could  continue  struggling  with  the  co-inhabitants  of  the  same 
region,  would  simply  add  one  more  to  the  myriads  which 
have  become  extinct. 

It  may  not  be  logical,  but  to  my  imagination,  it  is  far  more 
satisfactory  to  look  at  the  young  cuckoo  ejecting  its  foster- 
brothers,  ants  making  slaves,  the  larvse  of  the  Ichneumidfe 
feeding  within  the  live  bodies  of  their  prey,  cats  playing  with 
mice,  otters  and  cormorants  with  living  fish,  not  as  instincts 
specially  given  by  the  Creator,  but  as  very  small  parts  of  one 
general  law  leading  to  the  advancement  of  all  organic  bodies 
— Multiply,  Vary,  let  the  strongest  Live  and  the  weakest 
Die. 


1, 


'  I 


INDEX  TO  MENTAL  EVOLUTION  IN  ANIMALS. 


Abercrombie,  Dr.,  a  case  of  apoplexy  described  by,  38 
Abstraction,  145,  152-3,  352. 
Actinia.     See  Anemone, 
.^iian,  on  instincts  of  capon,  171. 
.^istbetic  emotions  in  animals,  311,  345. 
Affection  in  animals,  345. 
Aleipidce,  eyes  of,  85-6. 
Alford,  Lord,  hounds  of,  198.  241. 

Alison,  Professor,  on  sense  of  modesty  as  instinctive,  193. 
Allen^  Grant,  on  sense  of  temperature,  97;   on  sense  of  colour,  100;    on 
ratedd'oV240        '  ^^^~"'  o^s^^^e  of  dependence  shown  by  domesti- 
Amoeba,  power  of  discrimination  in,  55. 
Amphibia  senses  of  sight,  hearing,  smell,  taste,  and  touch  in,  90-  memorv 

m,  124  ;  grade  of  mental  evolution  of,  349-50. 
Amphioxus,  destitute  of  auditory  organs,  90, 
Anatomy,  relation  of  comparatiTe,  to  comparatire  psychology  5 
Andrews,  J.  B.,  on  homing  faculty  of  a  dog,  290. 
Anemone  sea-,  observation  upon  discrimination  of,  48-9  j   sense  of  smcU  in 

88  ;  mistaken  by  a  bee  for  a  flower,  168. 
Anger,  in  animals,  341,  345. 
^n«ej,^a,  consciousness  in,  77;   special  sensation  of,  56,  86;    emotions  of. 

344 ;  grade  of  mental  evolution  of,  344. 
Anthropoid  apes..     See  Ape. 

Ants  brain  of  ,46  J    memory  in,  146;    individual  yariations  of  instincts  of 
183  ;   local  variations  of  instincts  of,  244-5 ;    pets  of,  185  ;    receiving 
secretion    from    aphides,   277-8;    sense  of  direction   in,   295;    glave- 
niHking  instincts  of,  317 ;  grade  of  mental  evolution  of,  350 
Ape,  delusions  of  a  sun-struck,  150 ;  intelligence  of  an  anthropoid,  328. 
Apes,  anthropoid,  using  tools,  352 ;  grp,de  of  mental  evolution  of.  352 
Aphides,  yielding  their  secretion  to  ants,  277-8. 
Arachnida,  special  sensation  in,  56.     See  Spider  and  Scorpion. 
Argyll,  Duke  of,  on  an  eagle  teaching  a  goose  to  eat  flesh,  227';    on  origin  of 

instincts,  262  ;  on  instinct  of  feigning  injury,  316 
Articulata,  special  senses  of,  56,  84-8 ;    memory  in,  123 ;  imagination  in. 
145-6  {instinct  of  in  feigning  death,  303,  et  seq.;  emotions  of.  344 1 
grade  of  mental  evolution  of,  349. 
Association  of  Ideas.     See  Ideas. 
Ataxy,  analogous  to  lunacy,  44. 
Audouiii,  on  puppies  learning  to  imitate  cats,  223. 


:iii' 


386 


MENTAL  EVOLUTION  IN  ANIMALS. 


Auerhaoli,  on  rlilomma-time  in  perception,  134-6. 
Aurelia  anvita,  nervouB  system  of,  69. 


6. 

Bain,  Professor  Alexander,  on  associated  movements,  41,  43 ;    «"  a"9^'*; 

tiou  of  i.leas,   l:iO ;    on  perception,  125  ;    on  ideas  as  faint  revivals  of 

perceptions,  142-3  ;  on  evolution  of  mstmct,  256. 
Baines,  Mrs.  M.  A.,  on  a  puppy  learning  to  imitate  a  cat,  .J24. 
Banks.Sir  J.,  on  modified  instincts  of  a  spider,  209.  „«  i,„„f  f,„™ 

Barking,  inst  net  of,  round  a  carriage,  182  186  ,  instinct  of  an  offshoot  from 

acquired  instinct  of  protecting  master's  property,  23a  ;    not  practised  by 

does  in  certain  parts  of  the  world,  250. 
Bnrrington.  on  birds  acquiring  songs  of  their  foster  parents.  222. 
Bastian,  D^.,  on  sense  of  direction,  292-3  ;    on  mtelligenco  of  orang-outang, 

328. 
Bat,  sensibilitv  of  blinded,  94.  .  .      ...  .  *  u,„;„    a  a 

Bateman,  Dr." Frederick,  on  relation  of  intelligence  to  mass  of  brain,  44.   . 
Btites,  on  memory  of  Hymenoptera,  123. 

Batrachia.     See  Amphibia.  ,     ..       -  ♦•„„   mo 

Baxt.  on  reaction-time  as  increased  by  complexity  of  perception,  133. 

Bear,  becoming  omnivorous,  247.  n  •     t-   „*  *„  -„o<,«„  Jn 

Beaver,  local  variation  of  instinct  in,  249  j  relation  of  instinct  to  reason  m, 

329 

l:;s^trr"  ^nltii.' inSS  0T166-8, 174-5.  179,  203-9  ;  boring  hole, 
in  SL,  220-1;  local  variations  of  instincts  of.  245  ;  sense  of  direc- 
tion in,  290,  293-4;  cell-making  instinct  of,  317;  grade  of  mental 
evolution  of,  350. 

Beetles,  memory  in,  123;  instincts  of  dung,  241. 

Begging,  hereditary  transmisbion  of,  in  dog  and  cat,  1  Ja-t>. 

Belt,  on  memory  of  Hymenoptera,  123. 

Bembex,  instincts  of,  166,  191-2.  oak  a 

Benevolence,  in  animals,  341,  345  ;  in  cats,  345-0. 

Bennet,  on  birds  dreaming.  149. 

Beran,  the  Bev.  J.,  on  mistaken  instincts  of  bees  and  wasps,  167. 

Bidie.  G..  on  alleged  instinct  of  scorpion  to  commit  suicide.  2/8  ;  on  a  DUU 
feigning  death,  313-14. 

Bineley.  on  crabs  feigning  death,  305. 

Birds,  special  senses  of,  57 ;    sight,  91 ; 
touch,   92  ;    colour-sense,  99-100  ; 

dreaming,  149;  instincts  of  young, ,  --        -  ,     .    i. 

of  168  trivial  and  useless  instincts  of.  176;  attachments  between 
different  .pecies  of,  185.  and  with  other  animals  183-5 ;  varl^tlon8 
in  nest-building  of.  209-12;  variations  in  incubating  mstmcta  ot, 
212  17;  mtinctive' singing  of,  222;  imitating  songs  of  other  birds. 
222-3;  teaching  their  youlg,  226-7;  local  variatK)ns  of/°f;°°  J 
245-7  specific  variations  of  instinct  in,  251-5;  flying  towards  hght, 
279  mig^rn  of.  286-9,  2.5-7;  feigning  death.  303-5 ;  feigning 
injury.  316-17  ;  emotions  of.  345  ;  grade  of  mental  evolution  of,  351. 

Biscacha,  instinct  of,  190. 

Black.  William,  on  migration  of  swallows,  ^4b. 

Blackbird,  conveying  young.  211. 
Blackie,  Professor,  on  colour-sense,  100. 


hearing.  91-2;  smell,  taste,  and 
memory,  124 ;  perception.  131 ; 
161-5.  170-1;  mistaken  instincts 


li 


INDEX. 


387 


Blaine,  on  Lord  Alford's  hounds,  198 ;  on  inherited  tendency  to  bark  in 

Bporting  dog»,  23fi. 
Blue-bird,  local  variation  of  instinct  of,  210,  246. 
Blyth,  on  a  fox  feigning  death,  3U4. 
Bod,  on  carnivorous  habits  of  wasp,  245. 
Bond,  on  variation  in  nest  of  nut-hatch,  182. 
Bonelli,  Professor,  on  a  migration  of  butterflies,  288, 
Brain,  relation  of  intelligence  to  moss  of,  44-6. 
Brehm,  on  old  birds  educating  young,  226. 
Brent,  on  instincts  of  crossed  canaries,  199. 
Brewster,  Sir  D.,  on  unconscious  inference  in  perception,  321. 
Brodie,  Sir  B.,  on  infants  remembering  taste  of  particular  milk,  115  j  on 

inheritance  of  instinct  as  due  to  cerebral  organization,  264. 
Brunelli,  on  stridulation  of  grasshopper,  86. 
Bryden,  Dr.  W.,  on  a  monkey  feigning  death,  312-13. 
Buccola,  Dr.  Ot.,  on  length  of  the  reaction-time  in  perception  among  the 

uneducated  and  idiotic,  138. 
Buchanan,  Professor,  on  imperfect  instincts  of  young  ferrets,  228. 
Biichner,  on  individual  dispositions  shown  by  ants,  183. 
Bull,  wildness  of  cross  between  Indian  and  common  cow,  199;  Brahmin 

feigning  death,  313-14. 
Burdach,  on  imagination  in  animals,  151. 
Burrowing,  instinct  of,  248-9. 

Burton,  P.  M.,  on  mistaken  instinct  of  a  moth,  167. 
Butterflies,  littorul,  continuing  to  frequent  an  area  whence  the  sea  has  retired, 

246 ;  migration  of,  285-6. 


11  1 


0. 

Caddice-fly,  instincts  of  the,  191. 

Calderwood,  Professor,  on  the  relation  of  intelligence  to  the  mass  of  the  brain, 
44. 

Callin,  Or.,  on  sense  of  direction  in  man,  293. 

Cameleon,  sense  of  colour  in  the,  98. 

Canary,  diversity  of  individual  iiisposition  of  the,  182 ;  instincts  of  crossed 
breeds  of  the,  199  ;  instinctive  nidification  of  the,  226. 

Capon,  instincts  of  the,  171. 

Carpenter,  Dr.  W.  B.,  on  discrimination  shown  by  protoplasmic  organisms  ; 
on  acquired  habits,  181 ;  on  cats  not  howling  in  S.  America,  250  ;  on  a 
case  of  couching  for  cataract,  322 ;  on  inheritance  of  handwriting,  194. 

Carter,  H.  J.,  on  sensation  in  Rhizopoda,  80. 

Castration,  changes  produced  by,  on  instinct,  171-2. 

Cat,  idiosyncracies  of  the,  as  regards  mousing,  182  ;  associating  with  hares, 
&c.,  184  ;  hereditary  disposition  to  beg  in  a  family  of  the,  195  ;  rearing 
progeny  of  other  animals,  217-18 ;  loss  of  instinctive  wildness  of  the, 
under  domestication,  231 ;  not  howling  iu  S.  America,  249-50  ;  sense  of 
direction  in  the,  289  ;  cruelty  and  benevolence  in  the,  345-6  j  under- 
standing of  mechanism  by  the,  351. 

Caterpillar,  instincts  of  the  processional,  342-3. 

Caterpillars,  migrations  of,  285. 

Cattle,  learning  to  avoid  poisonous  herbs,  224,  227;  instincts  of  wild 
under  domestication,  231 ;  dwindling  of  natural  instincts  of  in  Ger- 
many, 232  ;  sucking  bones,  247  ;  sense  of  direction  in,  290. 

Causation,  appreciated  by  animals,  155-8. 


888 


MENTAL  EVOLUTION  IN  ANIMALS. 


Cephalopoda,  intoUigonce  of  reloted  to  organs  of  touoli,  67 1  oyei  of,  88  i 

enri>  of,  89  i  factilo  organi  of,  89  ;  colour-nenso  in,  98;  iDrn.ory  in,  \2'1  \ 

imagination  in,  145  ;  grade  of  uientul  oroluiion  of,  349-00. 
Cerebrum,  funotion»  of  the,  34-46. 
Chalicodoma,  instincts  of,  16H. 
Cliuracter,  individiiiil.    Sve  Disposition. 
Chelmon  roslratus,  89. 

Chesuldcn,  on  a  case  of  couching  for  cataraet,  322-8. 
Chickens.     See  Binls. 

Choice,  as  criterion  of  mind,  17-20;  physiological  ospcct  of,  47-56. 
Clifford,  Professor,  on  ejects,  16. 
Cobb,  Miss,  on  inheritance  of  handwriting,  194, 
Cwlenterata,  consciousness  in,  76,  348  ;  special  sense  of,  83-4 ;  emotions  of, 

342  ;  grade  of  mental  evolution  of,  348. 
Collett,  R.,  on  niigration  of  the  lemming,  283-6. 
Colour-sense,  98-104. 
Comparative  Psychology  in  relation  to  comparutiTC  anatomy,  6 ;  objects  of,  as 

a  science,  6-7. 
Comte,  on  B^etitihism  in  animals,  154. 
Conceptualism,  145. 
Conductility,  68. 
Conscience,  evolution  of,  352. 
Consciousness  as  the  distinctive  character  of  mind,  17  ;  evolution  of,  70-77  j 

definition  of  impossible,  72;    degrees  of,  72;    time  relations  of,  73; 

possibly  developed  to  supply  conditions  of  feeling  pleasure  and  pain.  111. 
Conte,  Le,  on  cattle  sucking  bones,  247. 
Couch,  on  mistaken  instinct  of  a  bee,  167-8 ;  on  variations  in  the  instinct  of 

incubation,  182;  on  a  dog  learning  how  to  attack  a  badger,  221;  on  a 

goldfinch  sinjiing  instinctively,  222 ;  on  birds  learning  and  forgetting  the 

snngs  of  other  birds,  223 ;    ou  the  instinct  of  feigning  death,  303-8, 

315. 
Coues,  Captain  Elliot,  on  local  variations  of  instinct  in  birds,  210,  246-7. 
Crab,  olfactory  organs    of,  87-8;  experiments  in  psychology  of  the  Hermit, 

122-3 ;  migration  of  the  Land,  146,  285 ;  feigning  death,  305 ;  reason 

in  the,  336,  350. 
Crayfish,  kataplexy  of  the,  308. 
Crc.r,  aquatic  habits  of  the,  253, 
Cripps,  on  an  elepliant  feigning  death,  305. 
Crocodile,  alleged  dreaming  iii  the,  149;  divers  dispositions  in  families  of  the, 

188. 
Crossing,  effects  of,  in  blending  instincts,  198-9. 
Crotch,  on  migration  of  the  lemming,  282-5. 
Cruelty  in  animals,  541,  345. 
Crustacea,  special  senses  of,  84,  87  ;  colour-sense  of   98-9     :  lemory  of,  122 

imagination  of,  145-6;  grade  of  mental  evolution  oi,  ^ii<-aO. 
Cuckoo,  mistaken  instincts  of  the,  168;  parasitic  and  no'.-par.  s^itic  habits  or 

the,  251-2 ;  parallelism  of  instincts  of  the,  with  r  '.ostJ  of  Moiothrut, 

273-4;  migration  of  the  young,  289. 
Cuculi<i(B.     iS'ee  Cuckoo. 
Curlew,  sense  of  hearing  in  the,  92. 
Curiosity  in  animals,  279-80,  341,  344. 
Cuttle-fish.     See  Cephalopoda. 
C"vi^r,  on  birds  dn-aming,  149. 
Cuvit.,  i*<,  ou  attaihuient  of  a  dog  to  a  lion,  184. 


INDEX. 


389 


D. 

Darwin,  Oharlen,  on  the  relation  of  intolligence  of  antu  to  tlio  nize  of  thoir  brnin«, 
45  j  on  movements  of  plants,  49-51  ;  on  iiitA-Uigence  o!  etirthworins,  77  i 
on  upeciftl  sonsos  of  earthworing,  8W-7  i  on  birds  (troaininjj,  149  j  on  nii«- 
taken  ing'inctn  of  luimblo-beos,  lfi8j  on  mLntiiktm  instinctn  of  an  African 
•lirow-nioiise,  1(59  j  on  vuriability  and  natunvl  deectioii  of  instinctn,  178  j 
on  inherited  tricks  of  nmnner,  18j  6 ;  on  inherited  pace»  of  the  horse, 
188  J  on  tumb'er  ard  Abvssinian  pigt>on»,  188-90 ;  on  instincts  of 
biscacha,  189-90;  on  inheritance  of  liandwriting,  194  j  on  wildness  and 
tanienesti  in  rabbits,  horses,  and  ducks,  196,  and  in  wild  animals,  197  ;  on 
effects  of  t  rossiiig  ujwn  instincts,  198-9 ;  on  intelligent  imitation  by 
animals,  220-2  ;  on  protrusion  of  lips  by  orang-outang,  225  •,  on  sheep 
and  cattle  learning  to  avoid  poisonous  herbs,  227  j  on  oblitemtion  of 
wild  instincts  under  domestication,  231-2 ;  on  acquisition  of  domestio 
instincts,  236-9 ;  on  bees  eating  moths,  245 ;  on  local  variations  of 
instinct  in  birds,  245-fi ;  on  the  hyccna  not  burrowing  in  South  Africa, 
249;  on  speciJic  variations  of  instinct  as  dilHcultios  against  the  theory  of 
natural  selection,  251 ;  on  parasitic  habits  of  Molothrua,  251 ;  on  ndoptivo 
structures  developed  by  natural  selection,  253-4;  on  evolution  of 
instinct,  261-6  ;  on  similar  instincts  of  unallied  animals,  273  ;  on  dis- 
similar instincts  of  allied  animals,  274 ;  on  trivial  and  useless  instincts, 
274-6 ;  on  instincts  apparently  detrimental,  276-82 ;  on  migration  of 
lemming,  282 ;  on  theory  of  migration,  287-97 ;  on  sense  of  direction, 
29u-3 ;  on  instincts  of  neuter  insects,  297-9 ;  on  instincts  of  sphex, 
299  and  303  ;  on  beos  boring  corollas  of  flowers,  220-1,  301-2  ;  on  instinct 
of  feigning  death,  308  j  on  instinct  of  feigning  injury,  316-17 ;  on 
reason  in  a  crab,  336 ;  on  emotions  of  earthworms,  344 ;  on  sexual 
•election,  344-5. 

[For  all  references  to  matter  now  published  in  the  Posthumous 
Essay  on  Instinct,  see  Index  to  the  Essay.  The  following  are  references 
to  all  the  quotations  from,  and  allusions  to,  the  unpublished  MSS  of 
Mr.  Darwin  which  occur  in  the  pages  of  the  present  work.] 

On  changes  produced  in  instinct  by  abnormal  individual  expe- 
rience, 115  ;  on  instinctive  fear  and  ferocity  in  young  animals  as 
directed  against  particular  enemies  or  kinds  of  prey,  165  ;  on  mistaken 
instincts  of  ants,  168 ;  on  instinct  of  a  kitten  modified  by  individual 
experience,  17:i ;  on  analogies  between  instincts  in  species  and  acquired 
habits  in  individuals,  179-80;  on  diversity  of  disposition  in  birds,  182  ; 
on  hereditary  tricks  of  manner  displayed  by  a  child,  185  6,  and  by  a 
terrier,  186 ;  on  peculiar  dispositions  and  habits  transmitted  in  croco- 
diles, ducks,  horses,  and  pigeons,  188- 9  j  on  autohiatic  actions  displayed 
by  idiots  and  by  an  idiotic  dog,  193  ;  on  instinctive  wildness  and  tame- 
ness  respectively  displayed  by  the  progeny  of  wild  and  tame  hor-es, 
rabbits,  and  ducks,  196 ;  on  effects  upon  instinct  of  crossing,  199 ;  on 
intelligent  modification  of  instinct  in  bees,  207  ;  on  wild  ducks  building 
in  trees,  211 ;  on  hive-bees  sucking  through  holes  made  in  corollas  by 
humble-bees,  220-1 ;  on  dogs  learning  modes  of  attack  by  experience 
and  imitation,  221 ;  on  birds  of  une  species  learning  danger  cries  of 
birds  of  another,  221-2 ;  on  a  dog  learning  by  imitation  the  habits  of  a 
cat,  and  lambs  and  cattle  learning  to  avoid  poisonous  herbs,  224 ;  on 
canaries  isared  in  a  felt  nest  afterwards  constructing  a  normal  nest,  226 ; 
on  the  non-instinctive  character  of  the  drinking  movements  of  chickens, 
228-9 ;  on  the  incorrigibly  wild  instincts  of  sundry  wild  animals  when 


:  -i! 


390 


MENTAL  EVOLUTION  IN  ANIMALS. 


ftif 


domesticated,  232 ;  on  the  stupidity  of  Chinese  dogs,  233  ;  on  the  arti^ 
ficially  bred  instincts  of  sheep-dogs,  pointers,  and  retrievers,  235-7  ;  on 
the  effects  upon  artilicially  bred  instincts  of  crossing,  241 ;  on  structures 
adapted  to  obsolete  uses,  253-4 ;  on  the  causes  of  the  evolution  of 
instinct,  264 ;  on  insects  flying  into  flame,  278-80 ;  on  the  instinct  of 
feigaing  injury  as  exhibited  by  the  duck,  partridge,  &c.,  316-17. 

Darwin,  T)r.  E.,  on  mistaken  instinct  of  Musca  carnaria,  167;  on  a  cat 
imitating  a  dog,  224;  on  eft'euts  of  domestication  on  instincts,  229;  on 
bees  ceasing  to  collect  honey  in  California,  245 ;  on  rabbits  not  bur- 
rowing in  Sor,  248. 

Darwin,  Francis,  oa.  bees  boring  holes  in  corollas  of  flowers,  302. 

Daphnea  pulex,  colour-sense  oi",  98. 

Davis,  on  instincts  of  the  processional  caterpillar,  342-3, 

Davy,  Sir  U.,  on  a'.i  eagle  teaching  young  to  fly,  2ii7. 

Death,  feigning  of,  by  animals,  303-16. 

Death-watch,  feigning  death,  309. 

Deceit,  in  animals,  341,  347. 

Delusions,  in  animals,  149-60. 

Diagram,  explanation  of  the,  63  9. 

Dilemma-time  in  perception,  134-5. 

DioncBd,  discrimination  sliown  by,  50-1. 

Diiecticn,  sense  of,  259-94.  . 

Discrimination,  in  relation  to  choice,  47-62 ;  shown  by  vegetable  tissues,  49- 
51 ;  by  protoplasmic  organisms,  51. 

Disposition,  individual,  of  men  and  animals,  182. 

Dog,  sense  of  smell  in  the,  93 ;  sense  of  musical  pitch  in  the,  94  ;  imagina- 
tion in  the,  146  and  148-9 ;  homesickness  and  pining  of  the,  as  proof  of 
imagination,  151-2 ;  appreciation  of  cause  by  the,  155-8 ;  instinct  of 
collie  barking  round  a  carriage,  182  ;  attachment  of  the  to  other  animals, 
184;  inherited  antipathy  of  a,  to  butchers,  187  ;  useless  instincts  of  the, 
176,  190 ;  instinct  of,  in  turning  round  to  make  a  bed,  193  ;  hereditary 
transmission  of  begsing  in  breeds  of  the,  195-6 ;  effects  of  crossing  upon 
insiincts  of  the,  198;  learning  by  imitation,  221,  223-4;  teaching 
young,  227  ;  influence  of  domestication  upon  psycholofjy  of  the,  231-42  ; 
barking  of  the,  249-55;  sense  of  direction  in  the,  289-90;  inabihty  of 
the,  to  appreciate  mechanism,  351 ;  grade  of  mental  evolution  of  the,  352. 

Domestication,  effects  of,  upon  instinct,  :;30-42. 

Donders,  Professor,  on  reaction-times  in  perception,  132,  135. 

Donovan,  on  cattle  sucking  bones,  247. 

Dragon-flies,  migrations  of,  286. 

Dreaming,  in  animals,  148-9. 

Drosera,  discrimination  sliown  by  tentacles  of,  49-50. 

Duck,  sense  of  touch  in  the,  92 ;  instincts  of  the  young,  171,  196  ;  a  breed  of 
showing  fear  of  water,  188  ;  natural  wildness  and  tameness  of  the,  196; 
instincts  of  the,  modified  by  crossing,  199  ;  conveying  young,  211 ;  build- 
ing on  trees,  211 ;  instinct  of  the,  in  feigning  injury,  316. 

Dudgeon,  P.,  on  a  cat  rearing  rats,  218.  ,     ,    j-      ao 

Dujardin,  on  relation  of  intelligence  of  ants  to  size  of  peduncular  bodies,  4b. 
Duncan,  on  spiders  feigning  death,  309. 
Duncan,  Professor  P.  M.,  on  instinct  of  Odynerus,  191-2. 


I j  lAlai««^BE«ifcifei  I  'i 


E. 

Eagle,  variation  in  nest-buildiiig  of  the,  182 ;  teaching  young  to  fly,  227 ;  teach- 
ing a  goose  to  eat  flesh,  227. 


INDEX. 


391 


Ear.     See  Hearing. 

Enrtliworma.     See  Worms. 

Earwig,  memory  in,  123 ;  parental  affection  of,  344. 

Echinudermata,  nervous  system  of,  28-30 ;  consciousness  in,  76,  348  j  special 

senses  of,  56,  84  ;  memory  in,  122,  348-9;  emotions  of,  342  j  grade  of 

mental  evolution  of,  348-9. 
Education  of  young  aninaals  by  their  parents,  226-9. 
Edward,  on  local  variation  of  instinct  in  the  swallow,  247. 
Eject,  16. 

Elam,  on  somnambulism  in  nnimals,  149. 
Elephant,  intelligence  of  the,  related  to  the  trunk,  57 ;  memory  in  the,  124; 

dreaming  in  ihe,  149;  instinct  of  the,  in  goring  wounded  companions, 

176 ;  feigning  death,  305 ;  emotions  of  the,  346 ;  using  tools,  352. 
Emotions,  physiological  aspect  of,  53 ;  which  occur  in  animals,  341 ;  origin 

of,  342 ;  distinctive,  of  different  animals,  34:.  -7. 

Emulation,  341, 345.  .  «.    i.  j  t. 

Engelmann,  on  protoplasmic  and  unicellular  organisms  being  affected  by 
light,  80;  on  one  infusorium  chasing  another,  81;  on  colour  sense  of 
Enfflena  viridis,  98. 

Englena  viHdis,  as  affected  by  light,  80 ;  colour  sense  of,  98. 

Equation,  personal,  135-7. 

E\olution,  Organic,  taken  for  granted,  7 ;  Mental,  a  necessary  corollary,  8; 
human,  excluded  from  present  work,  8-10;  of  nerves  by  use,  30-33;  of 
discriminative  and  executive  powers,  47-62;  of  mental  faculties  as 
shown  in  the  diagram,  63-9 ;  of  consciousness,  70-7 ;  of  sense  of  tem- 
perature, 97-8;  of  visual  sense,  97-8;  of  colour-sense,  98-103;  of 
organs  of  special  sense,  iP3-4 ;  of  pleasures  and  pains,  105-11  ;  of 
memory,  111-17  ;  of  association  of  ideas,  117-24 ;  of  perception,  127- 
9;  of  imagination,  144-54 ;  of  fetishism,  154-8 ;  of  instinct,  177- 255 ; 
of  reason,  318-35  ;  of  conscience,  352. 

Ewart,  Professor,  on  Echinodermata,  84 ;  on  colour-sense  of  Octojpus,  99. 

Excitability,  68. 

Excrement,  instinct  of  burying,  176. 

Exner,  Professor,  on  physiology  of  perception,  132-7, 

Eye.     See  Sight. 

Eyton,  on  instincts  of  crossed  Geese,  199. 


F. 

Fabre,  J.,  on  instincts  of  Bembex,  166,  and  of  Sphex,  179,  299-303 ;  on  sense 

of  direction  in  bees,  293-4. 
Fear  in  animals,  341 ;  in  young  children  and  low  animals,  342-3. 
Feeling.     See  Sensation. 
Feelings,  logic  of,  325. 
Feigning  death,  303-16 ;  injury,  316-17. 
Fenn,  Dr.  C.  M.,  on  imagination  in  a  wolf,  147. 
Ferrets,  reared  by  alien,  216-17  ;  imperfect  instincts  ot  young,  228;  analogy 

between  instincts  of,  and  those  of  Sphex,  303. 
Terrier,  on  functions  of  the  cerebrum,  35. 
Fish,  sense  of  sight  in,  89 ;  blind,  89  ;  luminous,  89 ;  sense  of  hearing  in,  90; 

of  smell,  taste,  and  touch,  90;  cf  colour,  98-9;    memory  in,  123-4; 

imagination  in,  153,  286 ;  feigning  death,  303 ;  emotions  of,  345  ;  grade 

of  mental  evolution  of.  349-50. 
Fish,  E.  E.,  on  birds  iniilating  each  other's  songs,  222 


■i  If 


392 


MENTAL  EVOLUTION  IN  ANIMALS. 


Fiake,  on  hereditary  transmission  of  begging  in  dogs,  165  ;  on  the  subordinate 
part  played  by  natural  selection  in  the  development  of  instinct,  256. 

Fitch,  Oswald,  on  benevolence  shown  by  a  cat.  345-6. 

FitzEoy,  Capt.,  on  instincts  of  wild  dogs  under  domestication,  232. 

Fleming,  on  delusions  shown  by  rabid  dogs,  149-50. 

Flesh-fly,  mistaken  instinct  of  the,  167. 

Flounder,  sense  of  colour  in  the,  98. 

Ford,  W.,  on  sense  of  direction  in  man,  291,  292. 

Forel,  on  variations  of  instinct  and  individual  dispo  ntion  in  ants,  183,  209, 
244-5. 

Fowl.     See  Hen. 

Fox,  the,  feigning  death,  304,  314-15  ;  understanding  of  mechanism  by  the, 
351. 

Fox,  the  Eev.  W.  D.,  on  inherited  tendency  to  beg  in  a  terrier,  186  ;  on  in- 
stincts of  a  retriever,  236. 

Fredericq,  on  colour-sense  of  Cephalopoda,  98-9. 

Fritsch,  on  functions  of  the  cerebrum,  35. 

Frog,  colour-sense  in  tl.e,  98  ;  changed  instincts  of  the  tree,  254. 

Furnarius,  imperfect  instincts  of  the,  281. 


(  I 


a 

Oalen,  on  instinct  of  a  kid,  115. 

Gallus  bankim,  wildness  of  chickens  reared  from  wild  stock  of,  232. 

Galton,  Francis,  on  hereditary  genius,  194. 

Ganglia,  structure  and  functions  of,  26-33  ;  Mr.  Spencer's  theory  of  genesis 

of,  32. 
Gardener,  J.  S.,  on  moths  flying  into  a  waterfall,  280. 
Gardner,  on  intelligence  of  a  crab,  336. 
Garnett,  on  instincts  of  crossed  ducks,  199. 
Gasteropoda,  eyes  of,  88  j  memory  in,  121.    See  Mollusca. 
Generalization,  145. 

Gentry,  W.  K.  G.,  on  carnivorous  habits  of  herbivorous  rodent,  248. 
Gladstone,  W.  E.,  on  colour-sense,  100. 
Goatsucker,  conveying  young,  211. 
Gold-crested  warbler,  nidification  of  the,  210. 
Goltz,  on  functions  of  the  cerebrum,  35. 
Goose,  eye  of  the  Solen,  91 ;  instincts  of  crossed,  199 ;  learning  to  eat  flesh, 

227  ;  instinct  of  upland,  253  j  Siberian,  feigning  death,  303-4  j  attftch- 

ment  of  a,  to  a  dog,  184-5. 
Goring,  instinct  of,  176,  379. 
Gosse,  on  gregarious  habits  in  nidification,  253 
Gould,  on  instincts  of  terrestrial  geese,  253. 
Grebe,  acjuatic  instincts  of  the,  253. 
Grief,  in  animals,  341,  345. 
Grouse,  instincts  of  North  American,  201. 
Guanacoe,  instincts  of  the,  190. 
Guer,  on  somnambulism  in  animals,  149. 
Ouyne,  on  migration  of  the  lemming,  282-6. 


H. 

Hffickel,    Professor,   on    sense-organs,    81,    S.^'-e ;    on  supposed  unknown 
sense  pobsessed  by  Fish,  90;  on  supposed  unknown  senses  possessed 


1 1 


INDEX. 


393 


ibordinate 
,256. 


183,  209, 

m  by  the, 
8  J  on  in- 


2. 

of  genesis 


I  eat  flpsh, 
4;  altftcli- 


unkno^^Ti 


by  MammalB,  95;  on  evolution  of  sense-organs,  98  104;  on  colour- 
sense,  100.  .  ...  ..■  1QQ 

Hall  G.  Stanley,  on  hypnotism  lengthening  reaction-time  m  perception,  IdS. 
HaniUton,  Sir  W.,  on  pleasures  and  pains,  105 ;  on  inverse  relation  between 

instinct  and  reason,  338. 
Hancock,  on  dogs  not  barking  in  Guinea,  250. 

Handcock,  on  obliteration  of  natural  instincts  under  domestication,  231. 
Handwriting,  inheritance  of,  194. 
Hate,  in  animals,  341,  345. 
Haust,  on  ducks  building  in  trees,  211. 
Hawfinch,  learning  the  song  of  a  blackbird,  222. 
Hawk,  eye  of,  91 ;  old,  teaching  young  to  capture  prey,  226 ;  changed  m- 

stincts  of  Swallow-tailed,  254.  „  ^     •     ,,  „  oo  n 

Hearing,  sense  of,  in  Medusae,  82;  in  Articulata,  86-7;  m  MoUusca,  88-9; 
in  Fish,  90;  in  Amphibia  and  Reptiles,  90;  in  Birds,  91-2;  in  Mam- 
mals, 93-4;  reaction-time  of,  132. 
Selix  pomatia,  memory  in,  122.  ,     u       e 

Helmholtz,  Professor,  on  reaction-time  as  increased  by  complexity  of  percep- 
tion, 133.  «  ,         ,  J      i.!. 
Hen,  instinct  of  cackling  in  the,  176,  289 ;  wildness  of  the.  when  crossed  with 
a  pheasant,  199 ;  conveying  young,  211 ;  experiments  and  observations 
on  the  incubating  and  natural  instincts  of  the,  213-17 ;  drinkjng  move- 
ments of  tlie,  not  instinctive,  229 ;  loss  of  incubating  instinct  of  the 
Spanish,  212. 
Hennabe,  on  the  byrax  dreaming,  149.                                   ,        .         x-        « 
Heredity,  in  relation  to  reflex  action,  17-18 ;  influence  of,  on  formation  of 
nervous  structures,  33 ;  in  association  of  ideas,  43 ;  in  reference  to  sensa- 
tion, 95-104 ;  to  pleasures  and  pains,  105-11 ;  to  memory  and  associa- 
tion of  ideas,  111-24 ;  to  perception,  130-41 ;  to  instinct,  180, 185-92, 
200-3    231-42 ;  of  handwriting  and  psychological  character,   194-5 ; 
of  begging  in  dogs  and  cats,  195-6 ;  of  wildness  and  tameness,  195-7  ; 
of  artificial  paces  in  horses,  188 ;  with  reference  to  migration,  289,  296-7. 
Hering,  on  muscle  strengthening  by  use,  112.                   .  ,     .     ,  ,        ,   , 
Herman,  on  reaction-times  of  different  senses,  132 ;  on  inherited  knowledge 

shown  by  sporting  dogs,  239. 
Eeteropoda,  eyes  of,  H8.  e  T,r  j        ca 

Hertwig,  Professors  O.  and  R.,  on  nervous  system  of  Medus(^,  bV. 
Hewetson,  on  variation  in  the  nest  of  the  nuthatch,  182. 
Hewett,  on  wildness  of  hybrids  between  fowls  and  pheasants,  199. 
Hill,  Richard,  on  gregarious  habits  in  nidifieation,  253. 
Hitzig,  on  functions  of  the  cerebrum,  35. 
Hofucker,  on  inheritance  of  handwriting,  194. 
HoH'mann,  Professor,  on  a  puppy  learning  to  imitate  a  cat,  224. 
Hogg,  on  instincts  of  a  sheep-dog,  240-1. 
Hollman,  on  memory  in  Cephalopoda,  122. 
Homing-faculty  of  aiumals,  95,  153-4. 
Home-sickness'in  animals,  proof  of  imagination,  151-2. 
Honig-Schnied,  on  reaction-time  for  taste,  133. 
Hon  ibill,  nidifieation  of  the,  255. 

Horse,  memory  in  the,  124;  inheritance  by  the,  of  artificial  paces,  188; 
useless  instincts  of  the,  190 ;  natural  tameness  of  the  leral,  196 ;  sense 
of  direction  in  the,  289-91. 
Houdin,  Robert,  remembering  his  art  of  iuggling  with  balls,  36;  on  rapidity 

of  perception  acquired  by  training,  138. 
House-fly,  mistaken  instinct  of  the,  167. 


394 


MENTAL  EVOLUTION  IN  ANIMALS. 


House-sparrow,  nidification  of  the,  210. 

Houzeau,  on   stridulation,  8fi ;   on  birds  dreaming,  149 ;  on  mistaken  in* 

stinctB,  167 ;  on  inability  of  infants  to  localize  pain,  326. 
Howitt,  A.  W.,  on  homing  faculty  of  horses  and  cattle,  290. 
Uuber,  on  instincts  of  bees,  168,  203-9. 
Huber,  P.,  on  instincts  of  a  caterpillar,  179. 
Huggins,  Dr.,  on  sense  of  musical  pitch  in  a  dog,  94;  on  inherited  antipathy 

of  a  dog  to  butchers,  187. 
Humboldt,  on  individual  disposition  in  monkeys,  188. 
Humming-bird  hawk-moth,  mistaken  instinct  of  the,  167. 
Hunger,  sense  of,  95. 

Hunter,  John,  on  tricks  of  manner  being  inherited,  185. 
Hurdis,  on  migration  of  the  golden  plover,  286. 

Hutchinson,  Colonel,  on  inherited  tendency  to  bark  in  sporting  dogs,  236. 
Hutton,  Captain,  on  wildness  of  the  hybrid  between  the  tame  and  wild  goat, 

199 ;  on  wildness  of  chickens  reared  from  wild  Oallus  bankiva,  2'o2  j  on 

migration,  288. 
Huxley,  Professor  T.  H.,  on  evolution  of  sense-organs,  104. 
JIt/drotoa,  nerve-tissues  in,  24. 
Hyaena,  not  burrowing  in  South  Africa,  244. 
Mylobates  agilis,  its  sense  of  musical  pitch,  93. 
Hymenoptera.     See  Ants  and  Bees. 

Hypnotism,  reaction-time  under  influence  of,  138 ;  of  animals,  308-11. 
Hyrax,  dreaming  in  the,  149. 


14  ,    It 


f-ri        t 


I   li 


Ichneumon,  instincts  of  the,  166. 

Ideas,  association  of,  37-8,  111-24;  definition  of,  118;  composite,  ana- 
logous to  muscular  coordinations,  42-4. 

Idiots,  size  of  brain  of,  in  relntion  to  intelligence,  45;  personal  equation  of, 
138 ;  tricks  of  manner  shown  by,  181 ;  automatic  actions  of,  193 ;  imita- 
tive actions  of,  225. 

Industry,  341. 

Imagination,  142-58 ;  analysis  of,  142-4 ;  stages  and  evolution  of,  144-5 ; 
stages  of,  as  occurring  in  different  animals,  1 45-54. 

Imitation,  effects  of,  on  formation  of  instinct,  220-9;  by  hive-bees  of 
humble  bees,  220-1 ;  by  dogs  of  other  dogs,  221 ;  by  dogs  of  cats,  223- 
4;  by  birds  of  one  another's  songs,  and  of  articulate  speech,  222-3  ;  by 
monkeys,  children,  savages,  and  idiots,  225 ;  by  young  birds  in  nidifica- 
tion sugLjestod  by  Mr.  Wallace,  225-6 ;  of  parents  by  young  of  sundry 
animals,  226-9. 

Incubation,  instinct  of,  177. 

Infant,  ccnscioix-ness  in  the,  77 ;  preferring  sweet  tastes,  and  remembering 
taste  of  milk,  114-16;  earliest  power  of  associating  ideas,  120-1,  and 
mental  images,  152  ;  when  spoon-fed  forgetting  to  suck,  170,  180 ;  learn- 
ing to  balance  the  head,  &c.,  175-6 ;  imitative  movements  of  the,  225 ; 
inability  of  the,  to  localize  pain,  326 ;  emotions  of  fear  and  surprise  in 
the,  342. 

Inference.     See  Reason. 

Infusoria.     See  Protozoa, 

Injury,  feigning  of,  by  animals,  316-17. 

Ii, sects,  eye?  of,  84-5;  colour-sense  of,  99;  imagination  of,  145-6;  instincts 
of,  1(35-8,  179,  201-2,  203-9,  220-1,  Z'^i,  277-81,  285-6,  290,  293-5, 
297 -3u9  i  emoiious  of,  34Ju 


INDEX. 


395 


Instinct,  pTiysiological  aspect  of,  52;  as  hereditary  memory,  115-17,  131 ; 
definition  of,  159;  involves  a  mental  element,  1(!0;  perfection  of, 
160-7 ;  in  voung  birds  and  mammals,  161-5 ;  in  inseots.  165-8,  179, 
201-2,  203-9,  220-1,  277-81,  285-6,  290-5,  297, -303-8;  of  Hying,  165; 
imperfection  of,  167-76;  as  affected  by  interruption  of  normal  con- 
vei'se  with  environment,  169-72,  by  castration,  171-2,  by  insanity, 
173-4;  trivial  and  useless,  176;  origin  and  development  of,  177-99; 
primary,  180-92 ;  secondary,  192-9 ;  ell'ects  of  crossing  upon,  198-9 ; 
blended  origin  or  plasticity  of,  200-218;  of  nidification,  210-12;  of 
incubation,  177,  212-13 ;  maternal,  212-18 ;  as  moulded  by  imita- 
tion, 219-25,  by  education,  226-9,  and  by  domestication,  230-42;  of 
singing  in  birds,  222-3  ;  of  attacking  rabbits  in  forrets,  228  ;  of  drinking 
in  fowls,  229 ;  local  and  specific  varieties  of,  2'13-55 ;  not  fossilized, 
250,  254-5 ;  evidence  of  transformation  yielded  by  specific  varieties 
of,  250-5 ;  views  of  other  writers  on  evolution  of,  256-72 ;  general  sum- 
mary on  and  diagram  of  development  of,  265-72  ;  cases  of  special  diffi- 
culty in  display  of,  273-317 ;  similar  in  unallied  animals,  273-4  ;  dis- 
similar in  allied  animals,  274;  trivial  and  useless,  274-6;  apparently 
detrimental,  276-85  ;  alleged,  of  scorpion  in  committing  suicide,  278 ;  of 
flying  throngh  flame,  278-80 ;  of  hen  cackling,  pheasant  crowing,  shrew- 
mouse  screauiing,  &c.,  280-1 ;  of  migration  injurious.  281-5;  of  lemming, 
282-5  ;  of  migration,  285-97  ;  of  neuter  insects,  265,  207-9;  of  sphex, 
299-303;  of  feigning  death,  303-16;  of  feigning  injury,  316-17;  in 
,  relation  to  reason,  338-9. 


J. 

Jackson,  C.  J.,  on  instinct  of  the  Californian  woodpecker,  255, 

Jackson,  Dr.  J.  Hughlings,  on  pre-perception,  139. 

Jealousy,  341,  315. 

Jeens,  C.  H.,  on  a  puppy  learning  to  imitate  a  cat,  224. 

Jelly-fishes.     See  MeduscB. 

Jerdon,  on  birds  dreaming,  149. 

Jesse,  on  changed  instincts  of  a  hen,  215;  on  snakes  feigning  death,  305. 


E. 


Kataplexy.     See  Hypnotism. 

Kidd,  W!,  on  diversity  of  disposition  in  larks  and  canaries,  182. 

Kingsley,  Canon,  on  migration  of  birds,  296. 

Kirby,  on  modified  instincts  of  larva',  180. 

Kirby  and  Spence,  on  larvae  remembering  tlie  taste  of  particular  leaves,  115; 

on  instincts  of  insects,  lb6,  167,  179-80,  201,  201-8,  244,  245. 
Kittens,  instincts  of,  164-5,  172. 
Knight,  Andrew,  on  liereditary  transmission  of  acquired  mental  endowments 

in  animals,  195,  197,  198,  237,  238 ;  on  intelligence  of  a  bird,  201,  and 

of  bees,  208. 
Knox,  D  E.,  on  a  variation  in  nest-building  of  the  golden  eagle,  182. 
Kries,  on  dilemma-time  in  perception,  134-5. 
Kuszmaul,  Prolessor,  on  infants  preferring  sweet  tastes,  116. 


i 


If ; 


tr; 


396 


MENTAL  EVOLUTION  IN  ANIMALS. 


lamarck,  his  theory  of  evolution  of  nerves  by  use,  33. 

LamellibrancMata,  eyes  of,  88. 

Landrail,  feigning  death,  304-5. 

Language,  as  mental  symbolism,  153. 

Lankester,  Professor,  on  alleged  instinct  of  scorpion  to  commit  suicide,  278. 

Lapsing  of  intelligence,  178-80. 

Lapwing,  habit  of,  in  flying  down  to  sportsman  when  fired  at,  189  ; 
associating  with  rooks  and  starlings,  185 ;  instinct  of,  in  feigning  death, 
317. 

Lasius  aeerborum.  local  variation  of  instinct  of,  244-5. 

Leech,  Dr.,  on  modified  instincts  of  a  spider,  209. 

Lemming,  migratory  instincts  of  the,  169,  282-5. 

Lepidoptera,  sense  of  hearing  in,  86.     See  Butterfly. 

Le  Roy,  on  imau'ination  of  animals,  146-7. 

Leuret,  on  intelligence  of  an  orang  outang,  328. 

Leveret,  roared  by  a  cat,  217. 

Lewes,  Q-.  H.,  case  of  sleeping  waiter  described  by,  36;  on  sensationp  as 
groups  of  components,  41 ;  his  definition  of  Sensation,  78 ;  on  pre- 
peneption,  139 ;  on  instincts  of  ducklings,  171 ;  on  hereditary  irans- 
mission  of  begging  in  dogs,  195;  ignores  natural  selection  in  development 
of  instinct,  256. 

Lewis,  on  carnivorous  habits  of  wasp,  245. 

Limpet,  memory  in  the,  121. 

Lindsay,  Dr.  Lauder,  on  dreaming  and  delusions  in  animals,  148-9. 

Linnceus,  on  dogs  not  borking  in  S.  America,  250. 

Lodge,  Colonel,  on  sense  of  direction  in  man,  293. 

Logic  of  feelings  and  signs,  325.  "^ 

Lonbiere,  on  local  variations  of  instinct  in  ants,  244. 

Lonsdale,  on  memory  in  a  snail,  122. 

Lord,  J.  K.,  on  instinct  of  the  CaUfornian  woodpecker,  255. 

Lubbock,  Sir  John,  on  deafness  of  ants,  86 ;  on  sense  of  smell  in  ants,  87 1 
on  colour-sense  of  Daphnea  pulex  and  Mymenoptera,  98-9 ;  on  memory 
of  bees,  123  ;  on  sense  of  direction  in  Hymenoptera,  293-5. 

Lucretius,  on  dreaming  in  dogs,  148. 

Ludicrous,  emotion  of,  in  animals,  341,  347. 

Lunacy,  analogous  to  ataxy,  44. 

Lyon,  Captain,  on  a  wolf  feigning  death,  304. 


fi    ' 


f 

^i;; 

'.' 

"'^i 

L 

,r  1 1 

M. 

MacFarlane,  Mrs.  L.,  on  changed  instincts  of  fowls,  215. 

Muckillar,  Miss,  on  changed  instincts  of  a  hen,  215. 

Macpherson,  H.  A.,  on  benevoh  nee  shown  by  a  cat,  346. 

Macroglossa  siellatarum,  mistaken  instinct  of,  167. 

Magnus,  Aibertus,  on  instincts  of  the  capon,  171. 

Matrnus,  Dr.,  on  colour-sense,  100. 

Malle,  Dureau  de  la,  on  inheritance  by  horses  of  artiQcial  paces,  188 ;  on 
birds  imitating  the  songb  of  other  birds,  222  ;  on  a  terrier  imitatins;  a 
cat,  2:<3-4  ;  on  old  birds  educating  ^  oung,  226 ;  on  instinct  of  burying 
■upurfluous  food,  233. 


INDEX. 


397 


Mammals,  speoial  Bonses  of,  57;  sight,  92;  hearing,  93-4;  taste  and  touch, 
94;  colour,  99  ;  memory  of,  124;  perception  of  young,  131 ;  imagina- 
tion of,  146-54;  inetinctB  of  young,  164-5;  mistaken  instincts  of, 
169;  trivial  and  useless  instincts  of,  176;  attachment  between  dif- 
ferent species  of,  and  with  other  animals,  184-5  ;  imitation  in,  223-5; 
teaching  their  young,  227;  local  variations  of  instinct  in,  247-50;' 
migrations  of,  286 ;  homing  faculty  of,  289-91 ;  feigning  death,  304^5  ; 
emotions  of,  345-7. 

Man,  mental  evolution  of,  questioned  by  some  evolutionists,  8-10;  subjective 
and  ejeotive  evidence  of  mind  in,  15,  et  seq. ;  relation  of  size  of  brain  of, 
to  intelligence,  46  ;  substitution  of  ma<hinery  by,  for  muscular  action, 
59 ;  imagination  in,  144,  152-4  ;  sense  of  direction  in,  291-3  ;  imperfec- 
tion of  hereditary  endowments  of,  326;  reason  alleged  special  pre- 
rogative of,  335-40. 

Mania,  analogous  to  convulsion,  44. 

Marshall,  Professor  John,  on  sense  of  smell  in  Octopus,  89 ;  on  sense  of  sight 
in  Surinam  Sprat,  90. 

Martins,  nidification  of,  210-11 ;  wavnirg  chickens  agninst  hawks,  221-2. 

McCready,  on  larvee  of  a  Medusa  sucking  tlieir  parent,  259-60. 

MeduscB,  larv8B  of,  sucking  parent,  259-60 ;  following  light  not  instinctivH, 
258;  nervous  system  of,  24,  28  ;  special  sensation  in,  56,  81-83. 

Melanerpesformicivorus,  peculiar  instinct  of,  255. 

Memory,  of  ganglia  without  consciousness,  35-6;  analysis  of,  111-17;  of 
infant,  114-16,  120-1;  in  MoUusca,  121-2;  in  Eehinodermata  and 
Crustacea,  122 ;  in  Insects,  123 ;  in  Fish,  123 ;  in  other  Verlebrata, 
124;  as  involved  in  perception,  129-30. 

Merejkowsky,  on  colour-sense  of  Dapknea  pulex,  98. 

Merganser,  instinct  of  the,  in  feigning  injury,  316. 

Merrill,  Q-.  C,  on  sense  of  direction  in  man,  292. 

Mierzejewskis,  Dr.,  on  relation  of  intelligence  to  mass  of  brain,  44. 

Migration,  281-97. 

Mill,  James,  on  composite  ideas,  44. 

Mill,  J.  S.,  ignores  heredity,  253  ;  on  reason,  336-7. 

Milton,  on  reason  of  animals,  340 ;  on  imagination,  154. 

Mind,  Criterion  of,  15-23 ;  considered  as  subject,  object,  and  eject,  15-16  ; 
activities  indicative  of,  16 ;  physical  basis  of,  34-46 ;  root-principles  of, 
47-62. 

Missel-thrush,  variation  in  nest  -building  of  the,  182. 

Mitchell,  Sir  J.,  on  dogs  learning  how  to  attack  the  Emu,  221. 

Mivart,  St.  G-.,  on  reason,  325,  335-40. 

M'Lachlan,  R.,  on  instincts  of  the  Caddice-fly,  191. 

Mocking-bird,  222. 

Modesty,  sense  of,  193. 

Moggridge,  on  instincts  of  ants,  168,  and  on  individual  variations  of  the  same, 
183. 

MoUusca,  consciousness  in,  77 ;  special  senses  of,  56,  88-9 ;  memory  in, 
121-2;  imagination  in,  145-6;  emotions  of,  344;  grade  of  mental  evolu- 
tion of,  349. 

Molothrus,  parasitic  instincts  of,  251-2,  273-4. 

Monboddo,  Lord,  on  homing  faculty  of  a  snake,  153-4. 

Monkeys,  sense  of  musical  pitch  shown  by,  93;  imagination  in,  151 ;  dif- 
ferences in  disposition  of,  188 ;  instinctive  dreud  of  snakes  shown  by, 
195  ;  love  of  imitation  shown  by,  225 ;  feigning  death,  311-12 ;  using 
tools,  252. 

Montagu,  Col.,  on  attachments  between  animals  of  different  species,  1S4-5. 
96 


398 


MENTAL  EVOLUTION  IN  ANIMALS. 


If; 

"if 


Montaigne  on  dreaming  in  animals,  148. 

Morality,  indefinite,  and  evolution  of,  352. 

Morgan,  Lewis  H.,  on  intelligence  of  the  beaver,  329. 

Morgan,  Professor  Lloyd,  on  alleged  instinct  of  the  scorpion  to  commit 
suicide,  278. 

Moseley,  Professor  H.  N.,  on  colour-sense  of  marine  animals,  99 ;  on  imper- 
fection of  instinct  in  honey-sucking  insects,  167 ;  on  beavers  of  Oregon 
not  constructing  dams,  249 ;  on  migration  of  turtles,  28d. 

Mouse  feigning  death,  306-7. 

Muaca  carnaria,  mistaken  instinct  of,  167. 

Muscles,  coordination  of,  an  index  of  nerve  evolution,  38-44i 

Mysis,  ear  of,  87 ;  colour-sense  of,  98. 

Mysteriousness,  sense  of,  in  animals,  155-8. 


N. 

Natural  selection.     See  Heredity. 

Nerve-tissue,  structure  and  function  of,  24-33. 

Neurility,  68. 

Newall,  on  carnivorous  habits  of  wasps,  245. 

Newbury,  Dr.,  on  beavers  not  constructing  dams,  249. 

Newton,  Professor  A.,  on  attachments  between  birds  of  different  species, 
185  ;  on  starlings  imitating  ducks,  222  ;  on  instincts  of  ring-plover,  246  j 
on  birds  flying  towards  light,  279 ;  on  migration  of  birds,  286-7,  295. 

Nidification,  variations  in  instinct  of,  182  ;  supposed  to  be  due  to  imitation, 
225-6 ;  associated,  253  ;  of  Thrush  and  Hornbills,  255. 

Nightingale,  midnisht  singing  of,  inherited,  246. 

Noulet,  on  nidification  of  swallows,  211. 

Nuthatch,  variation  in  nest-building  of  the,  182. 


0. 

Octopus,  eye  of,  88 ;  olfactory  sense  in,  89  5  imagination  in,  146  j  sense  of 

colour  in,  98-9. 
Odynerus,  instinct  of,  171  -2. 
Offspring,  recognition  of,  349. 

Orang-outang,  protrusion  of  lips  by  the,  225  ;  intelligence  of  a,  328. 
Oriole,  Baltimore,  improvement  of  nest-building  of  the,  210. 
Orthoptera,  ears  of,  87. 
Osmia  aurutenta,  208. 
Osmia  bicolor,  208. 
Ostrich,  caponizing  of  the,  172. 

Owl,  local  variation  of  instinct  of  the,  210,  246;  nidification  of  the,  210. 
Oyster,  memory  in  the,  121. 


P. 

Packard,  on  local  variation  of  instinct  in  bees,  245. 
Paget,  Sir  James,  on  a  parrot  learning  to  open  a  lock,  351. 
Pains,  105-11. 
Paley  on  direction  of  the  external  ear  93. 


INDEX. 


399 


Paralysis  analogous  to  unconsciousness,  44. 
Parental  affection  in  animals,  344. 

Parrot,  intelligence  of  the,  related  to  organs  of  touch,  57 ;  sense  of  touch  in 
the,  92;  association  of  ideas  in  the,  124;  dreaming  nnrt  talking  in  sleep, 
149;  mistaken  instinct  of  the  Australian,  167;  imitating  other  birds, 
talking,  and  singing,  223  ;  carnivorous  tastes  developed  by  the  Mountain, 
248  ;  changed  instincts  of  the  Ground,  254  ;  learning  to  open  a  lock,  351. 
Partridge,  conveying  young,  211 ;  not  using  voice  when  flushed  in  Ireland, 

245  ;  instinct  of  the,  in  feigning  injury,  317. 
Passu,  aquatic  habits  of,  253. 
Pea-fowl,  213-14. 

Peccari,  attachment  of  a,  to  a  dog,  184. 

Perception,  125-41 ;  definition  of,  125-6 ;  eTolution  of,  127-9 ;  as  cogni- 
tion, 127  ;  as  recognition,  127-8  ;  as  grouping  of  previous  perceptions, 
128;  tw  involving  inference,  128,  and  memory,  129;  as  affected  by 
heredity,  130-1 ;  in  Mammals,  Birds,  Reptiles,  and  Invertebrata,  131 ; 
physiology  of,  132-41;  time  relations  of,  132-9;  relation  of,  to  reflex 
action,  139-41;  as  stimulus  to  instinctive  action,  159-60;  illusions  of, 
321-2 ;  relation  of,  to  reason,  319-26. 
Petrel,  changed  instincts  of  the,  254. 

Pewit.     See  Lapwing.     Flycatcher,  variation  of  instinct  of  the,  210,  246. 
Pheasant,  crowing  of  the  cock,  176,  280  ;  wildness  of  hybrid  between  the, 

and  fowl,  199. 
Pig,  instincts  of  young,  164 ;   becoming  omnivorous,  247 ;  homing  faculty 

of  the,  290. 
Pigeon,  insane,  173-4;  tumbler,  188-9;  Abyssinian,  189;  pouter,  189;    in- 
stinctive fear  of  the,  of  cats,  lost  under  domestication,  232  ;  migration  of 
the  passenger,  281. 
Pike,  W.,  on  an  eagle  teaching  a  goose  to  eat  flesh,  227. 
Pining  in  animals,  proof  of  imagination,  151-2. 
Pitch,  musical,  appreciated  by  birds,  91 ;  by  Bylooates  agilis,  93  j  and  by 

dogs,  94. 
Play,  341,  345. 
Pleasures,  105-11. 

PleuronectidcB,  sense  of  colour  in,  98. 
Pliny  on  instincts  of  the  capon,  171. 
Plover     See  Ring-plover  and  Lapwing. 
Pointer.     See  Dog. 

Polecat,  instinct  of  the,  in  paralyzing  frogs,  303, 
Pollock,  Walter,  on  sense  of  smell  in  actinia,  83  ;  on  association  of  ideas  in 

a  parrot,  124 ;  on  delusions  in  a  dog,  150. 
Pope  on  instinct  and  reason,  266. 

Potts,  I.  H.,  on  carnivorous  tastes  developed  by  parrots,  248. 
Pouchet,  on  relation  between  instinct  and  reason,  339 ;  on  coloui-aense  of 

fish,  98 ;  on  nidification  of  swallows,  211. 
Pre-perception,  state  of,  139. 

Preyer,  Professor,  on  evolution  of  colour-sense,  101-4  ;  on  infants  preferring 
sweet  tastes,  114,  and  remembering  taste  of  milk,  115  ;  on  instinct  of 
chickens,  116-17  ;  on  rapidity  of  perception  acquired  by  training,  138  j 
on  infant  learning  to  balance  the  head,  &c.,  175-6  ;  on  imitative  move- 
ments and  dreaming  shown  by  the  infant,  225  ;  on  kataplexy  of  animals, 
308-11 ;  on  emotions  of  the  infant,  342,  344. 
Prichard,  on  a  puppy  reared  by  a  cat,  217,  224. 
Pride,  341,  345. 
Progeny,  yearning  for,  212-13. 


400 


MENTAI    EVOLUTION  IN  AMIMALS. 


Protiita  as  afPootod  by  light,  80-1. 

Protozoa  as  affected  by  light,  SO-1 ;  chasing  one  another,  81. 
Pteropoda,  eyes  of,  88. 
Pugnacity,  341,344. 

Pierguin  on  somnambulism  in  animals,  149;  on  delusions  of  an  ape,  lf>u. 
Psychology,  relation  of  Comparative  to  Comparative  Anatomy,  5  j  di.^tinctlon 
between,  and  Philosophy,  11. 

R. 

Babbit,  imagination  in  the,  147-8}  instinctive  antipathy  of  t>io  yp"ng  *« 
ferrets,  161-5 ;  imperfect  instinct  of  the,  with  regard  to  wnasels,  16y , 
natural  wildness  and  tameness  of  the,  19f5 ;  not  burrowing  m  Sor,  ;J48. 

Rae,  Dr.  J.,  on  instinct  of  ducks,  196  j  on  instinct  of  grouse,  201. 

Bage,  in  animals,  346. 

Ratel,  habit  of  the,  in  turning  somersaults,  189,  270. 

Bats,  understanding  of  mechanisms  by,  351. 

Battle-snake,  tail  of  the,  277. 

Eazor-fish,  memory  in  the,  122. 

Eeaction-time,  in  perception,  132-5.  j.     .• 

Beason,  physiological  aspect  of,  63 ;  supplementing  muscular  co-ordmntion 
by  machinery,  59 ;  definition  of,  318  ;  evolution  of,  319-35  ;  relution  ot, 
to  perception,  819-26;  grades  of,  318-25;  in  animal  kingdom  325-9 ; 
Mr  Spencer's  views  on  development  of,  330-5;  Mr.  Mivart  s  views 
upon,  335-40 ;  Mr.  Mills'  views  upon,  336-7 ;  in  relation  to  mstinct, 
330—40. 

Reaumur,  on  larvae  remembering  the  taste  of  particular  leaves, 
instincts  of  bees,  166 ;  on  instincts  of  the  capon,  171-2. 

Becognition  of  oH'spring,  349. 

BecoUection,  120. 

Boflection,  145.  .        „„  „„ 

Reflex  action,  explanation  of,  and  theory  of  its  evolution,  26-33 ;  arising 
from  habit,  38;  rise  of  consciousness  from,  74-5;  distinction  between, 
and  sensation,  78-9 ;  in  reference  to  memory  and  association  of  ideas, 
111-24 ;  to  perception,  139-41 ;  to  instinct,  159-60. 

Eegret,  in  animals,  347. 

Bhea,  mistaken  instinct  of  the,  168.  < 

Bemorse,  in  animals,  341.  ^    ,  -„  .,.    u 

E«ngger,  on  changed  instincts  of  a  wild  cat  in  confinement,  172;  on  attach- 
ment  of  a  monkey  to  a  dog,  184.  „    ,    ,  j  ^      i,    „*    on 

Reptiles,  sense  of  sight  in,  90;  hearing,  smeU,  taste,  and  touch  of,  90; 
colour  sense  of,  98;  memory  in,  tf4;  perception  m,  131 ;  imagination 
in,  149,  153-4 ;  migrations  of,  286 ;  feigning  death,  305 ;  emotions  ot, 
345 ;  grade  of  mental  evolution  of,  350. 

Resentment,  341,  345. 

Retriever.     See  Dog. 

Eevenge,  in  animals,  341,  346. 

Ehizopoda,  powers  of  special  aenie  in,  80. 

Eibot,  on  memory,  111-13.  ...     ,  oar 

Ring-plovers,  continuing  to  build  where  sea  has  retired,  246. 

Bomanes  a.  J.,  observations  on  MeduscB,  31-2;  on  sea-anemones,  48,  8.} ; 
on  Echinodermata,  84,  342,  348-9;  on  sense  of  hearing  in  Lepi- 
doptera  and  Birds,  86,  92;  on  sense  of  smell  in  crabs,  87-8;  on  sense 
of  musical  pilch  in  »  dog,  94;  on  colour-sense  of  Ootojius,  y8-9j  on 


115  :  on 


INDEX, 


e,  lf)0. 
distinction 


I  young  to 
isels,  16i)j 
Sor,  ;J48. 


401 


earliest  age  at  which  an  infant  is  able  to  assorinfo  ideas,  120-1.  on 
inability  of  hermit-cmb  to  associate  simple  ideas,  ._J  3:  on  time-rela. 
tions  m  perception    136-7;  on  sense  of  mysterious  in,  and  appreciation 

ffwriftZft  *''''  l^^'f'  °-  »"«*'"''"^e  antipathy  of  youn/r*bbits  to 
ferrets,  164-5 ;  on  handwriting,  19lj  on  incubatory  instincts.  213-11. 
on  animals  dying  of  terror.  307-8 ;  on  instincts  and  emotions  of  the  pro' 
cessional  caterpillar,  342-3  ' 

Rooks,  associating  with  starlings,  185. 

Rosa,  Baptista,  on  instincts  of  the  capon,  171. 

Ross,  Sir  J.,  on  dogs  learning  how  to  attack  wild  cattle,  221. 

Koulm,  on  cats  not  howling  in  South  America,  250. 

Routh,  Dr.,  OP  a  puppy  learning  to  imitate  a  cat,  224. 

Koy  Le.  on  imagination  of  wild  animals,  146-7  ;  on  mental  character!  of  a 
dog  of  wild  parentage,  198;  on  the  migration  of  birds,  289. 


■ordination 
reliition  of, 
•m,  325-9 ; 
irt's  views 
o  instinct, 

I,  115  ;  on 


33 ;  arising 
n  between, 
u  of  ideas, 


on  attach- 

3h  of,  90; 

magination 
motions  of, 


es,  48,  83  s 
»  in  Lepi- 
i ;  on  sense 
r,  y8-9j  on 


S. 

slimo^'^^i™'  p^'jf  ™y'  °°  intelligence  of  an  orang-outang,  328. 

Satiety,  sense  of,  95. 

Savag  sense  of  direction  in,  289,  291 5  tendency  to  imitation  shown  by, 

Schafer,  Professor  E.  A.,  on  nervous  system  of  Aurelia  aurita,  69. 

Schneider,  on  sense  of  vision  in  Serpults,  86. 

Scorpion,  alleged  instinct  of  the,  to  commit  suicide,  278 

Sebright.  Sir  J.    ou  natural  wildness  and  tameness  of  rabbits  and  ducVs, 

196;  on  instincts  of  an  Australian  puppy,  232;  on  love  of  man  as  in 

stmctive  in  domestic  dogs,  239. 
Seebohm,  on  migration  of  birds,  289. 
Scinut  hudsoniua,  change  of  instincts  in,  248. 
Seneca,  on  dreaming  in  dogs,  148. 
Sensation,  as  compound   40-1 ;  physiological  aspect  of,  51-2;  defined,  78, 

survey  of,  in  animal  kingdom,  8J-95 ;  of  temperature.  95-8;  of  colour 

actiraf  159-6?  perception,  125-6 ;  as  stimulus  to  reflex 

^'"'of riol?98-l(J4°^  ^'"'^'''  '^'"''  ""'^  '"*"**^'  ^^  •  "^  ^^•"P^rature,  96 -8 , 
Serpent.     See  Reptiles. 
Serpulce,  sense  of  vision  in,  86. 
Setter.     See  Dog. 

Sexual  affection  and  selection,  341,  344. 
Shame,  in  animals,  341,  347. 

Shaw,  J    on  stupidity  of  dogs  in  China  and  Polynesian  Ts-lands  033 
Sheep,  learnmg  to  avoid  poisonous  herbs,  224,  227;  changed  instincts  of 
under  domestication,  232;  killed  by  parrots,  248;  sense^f  direction  S, 

Sheep-dog.     See  Dog. 

Shrew-mouse  of  South  Africa,  injurious  instinct  of  the,  169  and  280. 
Shuttleworth  M,s8  C,  on  mistaken  instinct  of  bees  and  wasps,  167. 
Sight  sense  of,  in  Protista  81;  in  Medusa,  81-2;  in  EchiuodJrn.ata,  84;  of 
simple  and  compound  eyes,  84-5;  of  Worms,  85-6;  of  Fish,  89  ^  of 

tZ^^fV^^^'^''^''^  ^^-^ ',  °^  ^'''^''  91 '  °^  Mamm'als,  92 ;  lactic  u- 
time  ot,  133;  m  young  animals,  161-4, 

Sigismund,  on  infants  remembering  the  taste  of  milk,  114, 


402 


MENTAL  EVOLUTION  IN  ANIMALS. 


mi 


Signs,  logic  of,  326.         -  .     „« 

Skate,  olfactory  q;'«ans  of  the,  PO. 

Skylark,  folRning  death,  304..  .  qoq  a 

Smith,  Adam,  on  a  ca»o  of  couching  for  cataract,  3-3-4. 

Smith.  Dr.  Andrew,  on  hycena.  not  burrowing  m  South  Africa,  249. 

Smith,  F.,  on  instinct  of  beeB,  208.  ,:.„»;„„  oao 

Smith,  Col.  H.,  on  instincts  of  wild  dogs  under  domestication,  282. 

Smith,  W.  a.,  on  carnivorous  habits  of  wasps,  2io. 

Snail,  memory  in  the,  122.  ...      j     lu   nnK 

Snak;,  homing  faculty  of  the,  153-4,  f«>8"'"K  ^'"^^.V^J- .      ^^s    ants   and 

Smell  sense  of  in  Protista,  81 5  in  sea-anemones  83  ,  ^"J,''''^^^^^ 

crabs,  87-8  ;  in  MoUusca,  80  j  in  Fish,  Amphibia,  and  Reptiles,  W  ,  m 

Birds',  92 ;  in  Mammals,  92-3. 
Snipe,  sense  of  touch  in  the,  92. 
Social  feelings,  in  animals,  341,  344. 

IpSlit^DoS^on'&sUncts  of  young  birds  and  mammals.  161-6. 170-1. 

Spallanz'ani,  on  sensibiUty  of  blinded  bats,  94. 

Spaniel.     See  Dog. 

Speech,  acquirement  of,  by  Tolition,  41-.^. 

^P^^I:o:ZSL:^!^^-2.  on  consolidation  of  states 

^P"of  ;on  cTousne,B,42-3,  on  evolution  of  consciousness  74-6,  on  plea^ 
sures  and  pains,  105-7,  on  perception,  125 ,  on  memory,  129  30.  on 
«re-Dertept^on,  139  ,  on  perceptive  faculties  arising  from  reflex,  140,  on 
Fdeas  as  Snt  Revivals  o/^percVions,  U2-3 ;  -J«*'l'"r  on  e'E^n 
154-5  •  on  race  characteristics  in  psychology  of  man,  194,  on  evolution 
of  instinct,  256-62 ;  on  instincts  of  bees.  265. 

Sphex.  instincts  of  the,  179,  299-303. 

Sphinx-moth,  «»i«t'*''eni"f^i°'''°irM    damnation  in  the.  146,  modified 

303.    See  Arachnida. 
Sprat,  Surinam,  eye  of  the,  90. 
Squirrel,  a,  dying  of  terror,  307. 
Star-fish.     See  Echinodermata. 
Starlings,  associating  with  rooks,  185. 
Starling,  imitating  songs  of  other  birds,  iZ^-6. 
St  John,  on  inherited  tendency  to  bark  l"  ^P"''^.'"^ 'I"?''' f  6- 
S  ore  S    on  variation  in  nest-building  of  the  missel- thrush,  182 
Kd,  Dr  J.  W.,  on  change  of  instincts  produced  by  «istration,  171-2. 
Stuorn!  on  dwindling  of  maternal  instincts  of  cattle.  232. 
Sturm,  on  instincts  of  the  dung-beetle, -244.  ' 

tion,  321-2. 
Surinam  Sprat,  eye  of  the,  90. 

IwaC:  pSstfdty  and  local  variation  of  instincts  of  the.  210,  246-7 ,  migra- 

tion  of  the,  296. 
Swallows,  nidification  of,  210-11.  1.  lew 

S  wSon,  on  mistaken  instinct  of  the  Australian  parrot,  167. 
Swanderdam,  on  instincts  of  beee,  166. 


INDEX. 


403 


(Swift,  eye  of  the,  91. 
Sympathy,  341,  846. 


See  Swallow. 


Bparrow,  nidiflcation  of  the,  210 ;  ehani{o<l  instincts  of  a,  213  j  learning  lODg 
of  a  linnet,  222 }  local  variations  of  iuatinct  of  the,  247. 


T. 

Tachornia  phanicohea,  21 2. 

Tailor-bircf,  modifled  instincts  of  the,  210. 

Tait,  LawBon,  on  hereditary  transmission  of  begging  in  a  cat,  195. 

Tameness.     See  Wildness. 

Taste,  sense  of,  in  Protista,  81  j  in  Articulata,  88  ;  in  Fish,  90  j  in  Amphibia 
and  Reptiles,  90 ;  in  Birds,  92 ;  in  Mainmals,  94. 

Temmiek,  on  migration  of  birds,  289. 

Tonnent,  Sir  E.,  on  elephants  feigning  death,  306. 

Temperature,  sense  of,  85-8. 

Terrier.     See  Dog. 

Terror,  in  animals,  846. 

Thirst,  sense  of,  95. 

Thompson,  on  imagination  in  dogs,  146,  and  other  animals,  161 ;  on  crocodiles 
dreaming,  149  ;  on  horses  becoming  attached  to  dogs  and  cats,  184 ;  on 
effects  of  domestication  in  modifying  instinct,  242 ;  on  a  monkey  feign- 
ing death,  311-12. 

Thompson,  Rev.  L.,  on  bees  eating  moths,  2'15. 

Thomson,  Allen,  on  instinct  of  young  chickens,  163  ;  on  instinct  of  scorpion 
to  commit  sxiicide,  278  ;  on  benevolence  shown  by  a  cat,  346. 

Thrush,  sense  of  hearing  in  the,  92. 

Thwaites,  on  a  breed  of  ducks  showing  fear  of  watf^r,  188. 

Tiaropaia  indicans,  sense  of  touch  in,  83. 

Tiaropsis  polydiademata,  sense  of  sight  in,  81-2. 

Tickling,  caused  only  by  gentle  stimulation,  52. 

Touch,  sense  of,  in  plants,  49-51,  and  55 ;  in  Medusee,  Echinodermata, 
Mollusca,  and  Articulata,  56 ;  in  Vertebrata,  58 ;  in  Fisli,  Amphibia, 
and  Reptiles,  90  j  in  Birds,  92;  in  Mammals,  94;  as  origin  of  all 
special  senses,  103-4  j  reaction-time  of,  132. 

Trevellian,  on  mistaken  instinct  of  a  sphinx  moth,  167. 

Trichoptera,  instincts  of,  191. 

Tricks  of  manner  inherited,  181,  185-6  j  displayed  by  individuals, 
181-2. 

Turkeys,  instincts  of  young,  164,  175. 

Turtle,  migration  of  the,  286. 


u. 

UUoa,  on  dogs  not  barking  in  Juan  Fernandez,  250. 


V. 

Venus'  Fly-trap.     See  Dioneea. 

Venn,  on  association  of  ideas  by  talking  birds,  124. 

Villiers,  De,  on  instincts  of  the  processional  caterpillar,  342. 


404 


MENTAL  EVOLUTION  IN  ANIMALS. 


Vintflchgau,  on  reaction-time  for  taste,  133. 

Virchow,  Professor,  on  distinction  between  instinct  and  reason,  16"). 

Volition,  physiological  aspect  of,  53,  352. 

Vorticella,  chased  by  another  infusorium,  81. 

Vulture,  sense  of  sight  of  the,  91 ;  of  smell,  92. 


232;    on  instincts  of  crossed 


w. 

Wallace,  A.  E.,  on  evolution  of  Man,  9 ;  on  changed  instincts  of  nidification, 

212;  on  nidification  as  due  to  imitation,  225-6;   on  migration  of  the 

lemming,  283  ;  on  migration,  288 ;  on  homing  faculty,  291. 
"Water-hen,  aquatic  instincts  of  the,  253. 
Water-owzel,  changed  instincts  of  the,  254. 
Waterton,  on  instincts  of  young  pheasants, 

ducks,  199. 
Wasps.     See  Insects. 
Weasel,  feigning  death,  307. 
Weber,  on  sense  of  temperature,  96. 
Wedderbum,  Sir  D.,  on  carnivorous  liabits  of  wasps,  245. 
Weir,  on  Wallace's  theory  of  nidification  as  influenced  by  imitation,  226. 
Weissenborne,  on  a  migration  of  dragon-Hies,  286. 
Whately,  Archbishop,  on  cattle  sucking  bones,  247 ;   on  the  functions  of  the 

syllogism,  337. 
White,  C.  Coral,  on  a  fox  feigning  death.  814- 15. 
White,  the  Rev.  G-.,  on  loss  of  taste  for  flesh  shown  by  dogs  of  China,  233  ; 

on  a  leveret  reared  by  a  cat,  217. 
Widgeon,  attachment  of  a,  to  a  peacock,  183-4. 
Wildness,  acquired  instinct  of,  195-7, 
Wilks,  Dr.,  on  association  of  ideas  by  talking  birds,  124. 
Will.     See  VoUtion. 

Willoughby,  on  instincts  of  the  capon,  171. 
Wilson,  on  improved  nest-building  by  the  Baltimore  Oriel,  210. 
Wilson,  Sir  J.,  on  instincts  of  a  tamed  dingo  dog,  232. 
Wittich,  von,  on  reaction-time  for  ta-<te,  133. 
Wolf,  feigning  de  ith,  304 ;  imagination  in  the,  147. 
Wolff,  Madame  de  Meuron,  on  a  migration  of  buti  erflies,  285. 
Wolverine,  understanding  of  mechanism  by  the,  351. 
Woodcock,  wildness  and  tameness  of  the,  197 ;  carrying  young,  211. 
Wood-louse,  feigning  death,  309. 
Wood-pecker,  changed  instincts  of  the  Ground,  254 ;  peculiar  instincts  of  tlia 

Californian  in  storing  acorns,  255.      ' 
Worms.     See  Annelida. 
Wrangle,  on  geese  feigning  death,  303-4. 
Wren,  local  variation  of  instinct  of  the,  210,  246;  variation  in  nest-buildii^g 

of  the  golden-crested,  182. 
Wundt,  on  analogy  between  conscious  and  unconscious  memory,  114. 


Yarrel,  on  Birds,  222,  247. 

Youatt,  on  the  Dog,  150,  198,  241 ;  on  the  Sheep,  224,  227. 


Z. 
Zinken,  Dr.,  on  mistaken  instinct  of  flies,  167. 


INDEX. 


105 


INDEX  TO  Mr.  DARWIN'S  POSTHUMOUS  ESSAY. 


dification, 
on  of  the 


)f  crossed 


D,  226. 

}Ds  of  the 

lina,  233 ; 


1. 

nets  of  tha 

t-buildii:g 
L4. 


A. 

Alison,  on  instinct,  357,  367,  370,  375. 

Amhlyrhynchits,  tanieness  of,  361. 

Angoumois  moth,  double  instincts  of  the,  373. 

Antelopes,  migrations  of,  381. 

Ants,  ceasing  to  move  eggs  when  heat  is  supplied  to  them,  368 ;  instincts  of 

white,  376. 
Artamus  sordidus,  variations  in  nest-building  instincts  of,  373. 
Audubon,  on  nidification  of  Gulls,  36U,  and  of  Sterna  minuta,  372. 


B. 

Bachman,  on  migrations  of  the  bison  and  Canada  geese,  356 ;  on  migrations 

of  squirrels,  380. 
Banks,  Sir  J.,  an  changed  instincts  of  a  spider,  373. 
Barrington,  Hon,  Daines,  on  wildness  of  large  birds,  362. 
Beaver,  habitations  of  the,  372. 
Bechstein,  on  migratory  and  non-migratory  thrushes,  355 ;  on  variations  hi 

the  singing  of  nightingales,  374. 
Bees,  instincts  of,  in  making  queens.  376 ;  in  ventUating  hives,  378-9 ;  mis- 
taken instincts  of,  382-3  j  variation  in  instinct  of,  372-3  ;  pillaging  each 

other,  375. 
Birds,  migratory  habits  of,  355-9 ;  lameness  of,  in  islands  unfrequented  by 

man,   360-63 ;  nidification  of,   364-72 ;  variation  of  instinct  in,   374 ; 

instincts  of  small  in  mobbing  hawks,  382. 
Bison,  migrations  of  the,  355,  381. 
Bizcacha,  instincts  of  the,  379. 
Blackbirds,  nidification  of  a  pair  of,  371. 
Blackwal),  on  nidification,  371 ;  on  magpies  not  imitating  sounds  when  in  a 

state  of  nature,  374-5 ;  on  nidification  of  a  yellow  bunting,  371. 
Blyth,  on  instincts  of  removing  mutings,  &c.,  from  nests,  379  ;  on  the  wild  hen 

cackling  over  her  eggs,  381. 
Bonnet,  on  double  instincts,  373-4;  on  instincts  of  ants,  368. 
Botton,  on  nidification,  369. 

Bourgoanne,  on  migratory  instinct  of  sheep  in  Spain,  358. 
Brent  goose,  migratory  impulse  of  a  worn  out,  356. 
Brougham,  Lord,  on  instincts  of  chickens,  374. 
Bruce,  on  instincts  of  the  Bee-cUckoo,  382 ;  on  instincts  of  the  Abyssinian 

pigeon,  379. 
Buch,  von,  on  animals  dying  in  the  Solfortara  of  Java,  380. 
Buffalo,  migration  of  the,  355-6. 
Burrowing,  instinct  of,  372. 
Butcher-bird,  nidification  of  the,  382, 


406 


MENTAL  EVOLUTION  IN  ANIMALS. 


c. 

Carmichael,  Capt.,  on  tameness  of  birds  at  Tristan  d'Acunha,  361, 

Caterpillar.     See  Insects. 

Chaffinch,  nidification  of  a,  371< 

Chickens,  instincts  of,  374. 

Chrygomela,  feigning  death,  364. 

Clarke,  on  migration  of  the  bison,  881. 

Cluiscus,  feigning  death,  364. 

Colenso,  on  a  migratory  cuckoo  in  New  Zealand,  360. 

Vollocalia,  nidification  of,  365-6. 

Couch,  on  animals  feigning  death,  363 ;  on  nidification,  369,  370,  371. 

Corse,  on  elephants  attacking  companions  escaped  from  captivity,  381. 

Crow,  hooded,  fearlessness  of,  in  Egypt,  363. 

Cuckoo,  mistaken  instincts  of  the,  382 ;  instincts  of  the  Bee,  382. 

Curculia,  feigning  death,  364. 

Cuvier,  on  vocal  organs  oi  Passeres,  3^5. 


,.: 


J'  J  i ' ' . 


teaH 


D. 

D'Arbigny,  on  knowledge  of  time  shown  by  a  hawk,  357. 

Darwin,  Charles,  on  tameness  of  animals  in  islands  unfrequented  by  man, 
360-62 ;  on  a  lizard  feigning  death,  363-4 ;  on  nidification  of  Collo- 
calia,  365-6  ;  on  stupidity  of  Furnaritts  cunicularius,  371 ;  on  the  in- 
stinct of  burrowing,  372 ;  on  instincts  of  the  Guanaco  and  Bizcacha, 
379 ;  on  the  nidification  of  Furnarius,  382. 

Death,  feigning  of  by  animals,  363-4. 

Deer,  expelling  wounded  companions  from  herd,  376. 

De  Q-eer,  on  insects  feigning  death,  364. 

Direction,  sense  of,  shown  by  animals  and  men,  357-9. 

Dog,  instincts  of,  with  regard  to  excrement,  379. 

Du  Bois,  on  tameness  of  birds  at  Bourbon,  361. 

Duck,  fearlessness  shown  by  wild,  of  railway-trains,  362 ;  a  logger-headed, 
defending  a  goose  from  a  hawk,  381. 

Duges,  on  double  instincts  of  spiders,  374;  on  maternal  instincts  of  spider, 
382. 

E. 

Elephants,  attacking  companions  escaped  from  captivity,  381, 
Elk,  migrations  of  the,  360. 

F. 

Fischer,  Professor,  on  a  hen  incubating  her  eggs  in  a  hot- bed,  367. 

Fly-catcher,  a,  building  nest  upon  a  hot-house,  367. 

Fox,  wariness  and  tameness  of  the,  361. 

Fox,  the  Kev.  W.  D.,  on  the  nidification  of  a  pair  of  blackbirds,  and  a  pair 

of  redstarts,  371. 
Fremont,  Col.,  on  migrations  of  the  bison,  356. 
Furnarius  cunicularius,  stupidity  of,  371 ;  nidification  of,  381-2. 


G. 


Gad  fly,  instincts  of  the,  373. 


INDEX. 


407 


m. 

381. 


1  by  man, 
of  Collo- 

on  the  in- 
Bizcacha, 


»er-headed, 
of  spider, 


Golden -plover,  fearlessness  shown  by  the,  of  fire-arms,  363. 

Gold-finch,  nidification  of  the,  369. 

Goodsir,  on  fearlessness  shown  by  wild  ducks  of  railway  trains,  362. 

Goose,  migratory  impulse  of  a  Brent,  worn  out,  356 ;  the  Siberian  feigning 

death,  363. 
Goring,  instinct  of,  381. 
Gould,  on  migration  of  birds,  355 ;  on  nidification  of  Megapodida,  367 ;  of 

Artamus  sordidus,  372. 
Graber,  on  migratory  birds  of  Faroe,  360. 

Grey,  Sir  G.,  on  sense  of  direction  shown  by  native  Australians,  357. 
Gulls,  nidification  of,  369 ;  parasitic  instincts  of,  373. 
Guanacoes,  instincts  of,  379. 

H. 

Harcourt,  E.  V.,  on  non-migratory  habits  of  woodcocic,  356 ;    on  absence  of 

migratory  birds  in  Madeira,  359. 
Hare,  alleged  burrows  of  the,  372. 
Hawk,  knowledge  of  time  shown  by  a,  357;   timeness  of  a,  at  Galapagos 

Islands,  361. 
Hearne,  on  habitation  of  the  beaver,  372. 
Heineken,  Dr.,  en  non-migratory  habits  of  woodcock,  356. 
Hen,  wild  cackling  over  her  eggs,  381. 
Herbert,  Thos.,  on  tameness  of  birds  at  Mauritius,  361. 
Heron,  wildness  of  the,  362  ;  nidification  of  the,  369. 
Howitson,  C,  on  tameness  of  magpies  in  Norway,  363 ;   on  nidification  of  a 

chaffinch,  371. 
Eirundo,  migration  of,  358  ;  nidification  of,  365-6,  369-70. 
Histers,  feigning  death,  364. 
Hogg,  on  migratory  instinct  of  sheep,  358. 
Home,  on  structure  of  the  proventriculus  of  Collocalia,  366. 
Homing  faculty  in  animals,  358. 
Hogstrom,  on  migration  of  ermines,  380. 
Horse,  instincts  of  the,  with  regard  to  excrement,  379. 
House-fly,  instincts  of  the,  with  regard  to  excrement,  379. 
House-martin,  nidification  of  the,  365.     /See  Martin. 
Huber,  ou  bees  pillaging  each  other,  375 ;   on  mistaken  instincts  of  beei, 

382-3. 
Huber,  P.,  on  double  instincts  of  a  beetle  larva,  373. 
Hunt,  Consul  C,  on  birds  visiting  the  Azores,  358,  359-60. 
Hull,  the  Rev.  J.,  on  nidification  of  the  magpie,  370. 
Hyffiuas,  not  burrowing  in  S.  Africa,  372. 
Hyrax,  instincts  of  the,  with  regard  to  excrement,  379. 


and  a  pair 


Icterus  haltimore,  nidification  of,  372. 

Insects,  feigning  death,  363-4 ;  varied  instircts  of,  372-3 ;  double  instincts 
of,  373-4 ;  hatched  in  human  body,  375 ;  instincts  of,  exhibited  only 
once,  377  ;  instincts  of,  with  regard  to  excrement,  379 ;  migrations  of, 
378 ;  mistaken  instincts  of,  382-3. 

Instinct,  of  migration,  355-60 ;  of  ffar,  360-64 ;  of  nidification,  364-72  j 
double  in  certain  birds,  371-73,  and  in  certain  insects,  373-4 ;  of  mam- 
mals in  forming  habitations,  372-3  j  of  beaver  and  musk  rat,  372  j  of 


i^"V'V.''i«U-/ 


408 


MENTAL  EVOLUTION  IN  ANIMALS. 


burrowing,  372 ;  variations  in,  of  bees,  372-3  j  of  chickens  pecking  their 
■way  out  of  eggs,  374 ;  of  gad-fly,  375;  of  parasitism,  375-6;  of  bees, 
375-6 ;  of  Molothrus  and  white  ants,  376  ;  of  diguing  pitfalls,  376-7 ; 
alleged  to  be  detrimental  to  the  species  exhibiting  it,  377 ;  only  once 
Exhibited,  377-8;  differences  of,  in  related  forms,  378;  small  and 
trivial,  378-9;  of  removing  broken  eggs  and  mutings,  379;  of  Abya- 
•inian  pigeon,  Lagostomus,  and  Guanai'oes,  379 ;  with  regard  to  excre- 
ment, 379  ;  imperfect  and  mistaken,  380  ;  social,  381 ;  apparently 
detrimental,  381-83 ;  of  attacking  wounded  companions,  381 ;  of  cock 
pheasants  crowing  and  wild  hens  cackling,  381  ;  of  shrew-mouse  scream- 
ing, ostrich  scattering  eggs,  382 ;  at  fault  in  sundry  animals,  182-3. 

Ireland,  habits  of  animals  in.     See  W.  Thompson. 

Ischndi,  on  migratory  instincts  of  Alpine  cattle,  358. 

lulus,  feigning  death,  364. 

J. 

Jackdaw,  nidification  of  a,  370 ;  stupidity  of  a,  371. 

Jenyns,  the  Rev.  L.,  on  habitiitious  of  rats,  372 ;   on  insects  hatched  within 

the  human  body,  375 ;  on  crowing  of  the  cock  pheasant,  381. 
Jesse,  on  the  nidific<ition  of  a  jackdaw,  370. 


K. 

Knngnroo,  regurgital  ion  of  food  by  the,  374. 

Kirbv  iuid  Spence,  on  instincts  of  insects,  364,  368,  374,  375,  37G,  377,  378, 

379,  383. 
Knapp,  on  nidification  of  the  butcher-bird,  382. 


L. 

Lafjostomvs,  instincts  of,  401. 

Lamarck,  on  co-operation  of  sw&llows,  375. 

Larvae.     See  Insects. 

Lloyd,  L.,  on  migration  of  the  lemming,  380. 

Le  Roy,  on  wariness  of  foxes  and  wolves,  361, 

Lewis,  on  migration  of  the  bieon,  381. 

Le  Vaillant,  on  migratory  and  non-migratory  habits  of  quail,  355. 

Linneus,  on  instinct,  377. 

Livingstone,  on  instincts  of  hyrax,  379. 

Lizards,  wilduess  and  tameness  of,  356 ;  feigning  death,  363-4. 


M. 

Macgillivray,  on  nests  of  swifts,  365-fi,   of  kitty-wrens,  368  and  370,   of 

herons,  369 ;    on  cooperation  in  martins,  375 ;   ou  parasitism  in  gulls, 

375, 
Magpie,  fearlessness  of  the,  in  Norway,  362 ;  nidification  of  the,  370 ;  powers 

of  the,  in  imitating  various  sounds,  39t-.'>. 
Mammals,  migrations  of,  355-6,  358  9  j   instinctive  fear  shown  by,  361  j 

habitations  of,  372-3. 


INDEX. 


409 


king  their 
;  of  bees, 
Is,  376-7 ; 
only  once 
small  and 
of  Abya- 
to  excre- 
ipparently 
;  of  cock 
se  scream- 
82-3. 


Martin,  nidification  of  the,  364,  369,  370. 

Martins,  cooperation  shown  by,  375. 

Martin,  W.  C.,  on  regurgitation  of  food  by  the  Kangaroo,  374. 

MegapodidcB,  nidification  of,  367-8. 

Mice,  wariness  of,  362. 

Migration,  355-60;  of  young  birds,  355;  of  quail,  355 ;  of  buffalo,  3f5  6; 
theory  of,  359;  of  elk  and  reindeer,  360;  of  lemming,  squirrel,  and 
ermine,  380 ;  of  insects,  380 ;  of  pigeons,  antelopes,  and  bisons,  381. 

Molothrus,  instincts  of,  876. 

Montague,  on  nidification  of  sparrows,  369. 

Moresby,  Capt.,  on  tameness  of  birds  at  Providence  Islands,  361. 

Mosto,  Oada,  on  tameness  of  C.  de  Verde  Island  pigeons,  3U1. 

Musk-rat,  habitation  of,  372. 


led  within 


N. 

Nidification,  364-72;   of  swallows,  365-6;    of  MegapodidcB,ZQ1-S; 

tions  in  instinct  of,  3(i9-73 ;  double  instinct  oi,  371-72.    ' 
Tf  ightiugale,  variations  in  singing  of  the,  374. 


Taria- 


,  377,  378, 


Osmia,  variation  in  instincts  of,  372-3. 
Ostrich,  scaitcring  her  eggs,  382. 


P. 


Partridge,  variation  in  instincts  of  the,  373. 

Peabody,  on  nidification  of  Cypelus  pelasgius,  365  ;    of  kitty-wrens,  368 ;  of 

herons,  369  ;  of  Totanus  macularius,  371 ;  of  Icterus  baltimore,  H2i. 
Pheasant,  maternal  instincts  of  the  hen,  379 ;  crowing  instincts  of  cock,  381. 
Pigeon,  fearlessness  of  the,  at  C.  de  Verde  Islands,  361,  and  at  Galapagos, 

363 ;  instincts  of  the  Abyssinian,  379  ;  migration  of  the  Passenger,  381 ; 

instinct  of  the,  in  attacking  wounded  companions,  360. 
Ptinus,  feigning  death,  364. 
Pulet,  variations  of  pupa  of,  374. 


Quail,  migration  of  the,  355. 


Q. 


d  370,    of 

a  in  gulls, 

0 ;  powprg 
by,  361$ 


Eae,  Dr.  J.,  on  fearlessneBB  shown  by  birds  of  railway  trains,  362 ;  and  of 

firearms,  363. 
Kat,  musk,  habitation  of  the,  372. 
Bat,  wariness  of  the,  362. 
Eeaumur,  on  instincts  of  ants,  3fi8. 
E«dstarts,  nidification  of  a  pair  of,  371. 
Reindeer,  migrations  of  the,  360. 


410 


MENTAL  EVOLUTION  IN  ANIMALS. 


Reinwardts,  on  animals  dying  in  the  Solfortar«  of  Java,  380, 
Rieliardson,  on  nidification  of  American  swallows,  369-80. 
Roberts,  M.  E.,  ou  nidification  of  Mirundo  riparia,  365. 
Robin,  fainting  from  fright,  363  ;  nidification  of  the,  369. 


s. 

Salmon,  migrations  of  the,  355,  35S. 

Savi,  Dr.  P.,  on  the  double  instinct  o "  '  lon  shown  by  Sylvia  eisticola, 

371. 
Scope,  on  migration  of  salmon,  358. 

Scrope,  W.,  on  deer  expelling  wounded  companions  from  herd,  381. 
Sheep,  homing  faculty  of  Highland,  358;    migratory   instinct  of  Spanish, 

358-9. 
Sheppard,  on  the  nidification  of  a  golden-crested  wren,  371. 
Shrew-mouse,  instinct  of  a,  in  screaming  when  approached,  382. 
Smith,  Dr.  Andrew,  on  migrations  of  quail,  355}    on  hyttnas  not  burrowing 

in  S.  Africa,  372. 
Smith,  F.,  on  variations  in  instincts  of  bees,  372-3. 
Snake,  incubating  eggs  in  a  hot-bed,  367. 
Sparrow,  nidification  of  th^,  369. 
Spence,  on  migration  of  insects,  380. 
Spider,  feigning  death,  364 ;  changed  instincts  of  a,  373  ;   double  instincts  of 

the  hunting,  374 ;  maternal  instincts  of  the,  mistaken,  382  j  instinct  of 

the  female  to  devour  male,  383. 
Sterna  minuta,  variations  in  nest-building  instincts  of,  372. 
St.  Hilaire,  Geoffry,  on  tameness  of  hooded  crows  in  Egypt,  363. 
St.  John,  on  non-migratory  habits  of  woodcock,  356. 
Sullivan,  Captain,  on  a  duck  defending  a  goose  from  a  hawk,  381. 
Swallows,  migration  of,  358 ;  nidification  of,  365-6,  369-80 ;  cooperation  of, 

375. 
Swans,  nidification  of,  370. 

Swift,  non-migratory  habits  of  the,  356  ;  nidification  of  the,  365-6. 
Sylvia  eisticola,  double  instinct  of  nidification  shown  by,  371. 


ir  ' 


'<r.    t 


T. 

Taylor-bird,  nidification  of  the,  369. 

Thompson,  E.  P.,  on  instinct,  357  ;  on  wariness  of  rats  and  mice,  362. 

Thompson,  W.,  on  non-migratory  habits  of  quail  in  Ireland,  355,  and  of 
woodcock  in  Scotland,  356 ;  on  a  Brent  goose  losing  its  migratory 
instinct,  356;  on  N.  American  birds  visiting  Ireland,  358;  on  fearless- 
ness shown  by  birds  of  railway  trains,  362  ;  on  nidification  of  heron, 
369;  of  robins,  369;  of  water-hens,  370;  of  magpies,  370  ;  of  thrushes, 
371 ;  on  variations  in  instinct  of  partridties.  374. 

Thrush,  migratory  and  non-migratory  varieties  oi  the,  355  j  nidification  of  the, 
368-9,  371. 

Totanus  macularius,  nidification  oi',  371. 


w. 


"Water-hen,  nidification  of  the,  370. 
Water-ouzel,  nidification  of  the,  370. 


HTDEX. 


411 


eisticola, 
Spanish, 


Waterton,  on  insHncts  of  the  hen  pheasant,  379. 

Weaver-bird,  nidiflcation  of  the,  371. 

Weissenbom,  on  migrations  of  insects,  380. 

Westwood,  on  instincts  of  caterpillars,  373,  378. 

White,  the  Rev.  Q-.,  on  the  nidiflcation  of  a  willow-wren,  and  of  jackdaws, 

370 ;  of  martins,  371. 
Wolf,  wariness  and  tameness  of  the,  361. 
Woodcock,  migratory  and  non-migratory  haoits  of  the,  356. 
Wrangel,  on  sense  of  direction  shown  by  natives  of  N.  Siberia,  357  j  on 

Siberian  geese  feigning  death,  363. 
Wren,  nidiflcation  of  the,  368,  369,  370,  371. 


jurrowing 


Yarrel,  on  British  birds,  367,  369,  370,  371. 
Yellow  bimting,  nidiflcation  of  a,  371. 
Youatt,  on  sheep,  358. 


istincts  of 
nstinct  of 


jration  of, 


62. 

5,  and  of 

migratory 

1  fearless- 

of  heron, 

thrushes, 

on  of  the, 


